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Calculated Shard: 152 (from laksa032)

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curl -X POST \
  'http://laksa152.int.ahrefs:8124/' \
  -H 'Content-Type: text/plain' \
  -H 'X-ClickHouse-Database: crawler3' \
  -H 'Authorization: Basic YXBpOg==' \
  -d 'SELECT getAhrefsURLFromUnparsed(src_unparsed) AS found_url, ifNull(toUnixTimestamp(download_stamp), 0) AS crawl_time, ifNull(toUnixTimestamp(props_url_first_seen), 0) AS first_indexed_time, download_http_code AS http_code, src_unparsed AS src_unparsed, src_root_hash AS src_root_hash, history_drop_reason AS history_drop_reason, meta_title AS meta_title, meta_descriptions AS meta_descriptions, attrs_boilerpipe_text AS attrs_boilerpipe_text, attrs_markdown AS attrs_markdown, attrs_readable_markdown AS attrs_readable_markdown, meta_canonical AS meta_canonical FROM crawler3.page_info_local FINAL PREWHERE (src_root_hash, src_unparsed) IN ((getAhrefsRootHashFromUnparsed(getAhrefsUnparsedNoserviceFromURL(\'https://en.wikipedia.org/wiki/Event_Horizon_Telescope\')), getAhrefsUnparsedNoserviceFromURL(\'https://en.wikipedia.org/wiki/Event_Horizon_Telescope\'))) FORMAT JSONEachRow'

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{"found_url":"https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope","crawl_time":1773257153,"first_indexed_time":1426365690,"http_code":200,"src_unparsed":"org,wikipedia!en,\/wiki\/Event_Horizon_Telescope s443","src_root_hash":"17790707453426894952","history_drop_reason":null,"meta_title":"Event Horizon Telescope - Wikipedia","meta_descriptions":[],"attrs_boilerpipe_text":"From Wikipedia, the free encyclopedia\nEvent Horizon Telescope\nAlternative names\nEHT \nEstablished\n2009\n; 17 years ago\nWebsite\neventhorizontelescope\n.org\nTelescopes\nAtacama Large Millimeter Array\nAtacama Pathfinder Experiment\nGreenland Telescope\nHeinrich Hertz Submillimeter Telescope\nIRAM 30m telescope\nJames Clerk Maxwell Telescope\nLarge Millimeter Telescope\nSouth Pole Telescope\nSubmillimeter Array\n \n \nRelated media on Commons\n[\nedit on Wikidata\n]\nThe\nEvent Horizon Telescope\n(\nEHT\n) is a\ntelescope array\nconsisting of a global network of\nradio telescopes\n. The EHT project combines data from several\nvery-long-baseline interferometry\n(VLBI) stations around Earth, which form a combined array with an\nangular resolution\nsufficient to observe objects the size of a\nsupermassive black hole\n's\nevent horizon\n. The project's observational targets include the two\nblack holes\nwith the largest\nangular diameter\nas observed from Earth: the black hole at the center of the\nsupergiant\nelliptical galaxy\nMessier 87\n, and\nSagittarius A*\n, at\nthe center\nof the\nMilky Way\n.\n[\n1\n]\n[\n2\n]\nThe Event Horizon Telescope project is an international collaboration that was launched in 2009\n[\n1\n]\nafter a long period of theoretical and technical developments. On the theory side, work on the photon orbit\n[\n3\n]\nand first simulations of what a black hole would look like\n[\n4\n]\nprogressed to predictions of VLBI imaging for the Galactic Center black hole, Sgr A*.\n[\n5\n]\n[\n6\n]\nTechnical advances in radio observing moved from the first detection of Sgr A*,\n[\n7\n]\nthrough VLBI at progressively shorter wavelengths, ultimately leading to detection of horizon scale structure in both Sgr A* and M87.\n[\n8\n]\n[\n9\n]\nThe collaboration now comprises over 300\n[\n10\n]\nmembers, and 60 institutions, working in over 20 countries and regions.\n[\n11\n]\nThe first image of a black hole, at the center of galaxy Messier 87, was published by the EHT Collaboration on April 10, 2019, in a series of six scientific publications.\n[\n12\n]\nThe array made this observation at a wavelength of 1.3 mm and with a theoretical\ndiffraction-limited resolution\nof\n25\nmicroarcseconds\n. In March 2021, the Collaboration presented, for the first time, a\npolarized-based image\nof the\nblack hole\nwhich may help better reveal the forces giving rise to\nquasars\n.\n[\n13\n]\nFuture plans involve improving the array's resolution by adding new telescopes and by taking shorter-wavelength observations.\n[\n2\n]\n[\n14\n]\nOn 12 May 2022, astronomers unveiled the first image of the supermassive black hole at the center of the\nMilky Way\n,\nSagittarius A*\n.\n[\n15\n]\nSince 2018 the EHT has been capable of imaging at a wavelength of 870 μm (345 GHz), giving an angular resolution of 19 μas, the best resolution of any ground-based telescope.\n[\n16\n]\nA schematic diagram of the VLBI mechanism of EHT. Each antenna, spread out over vast distances, has an extremely precise\natomic clock\n.\nAnalogue signals\ncollected by the antenna are converted to\ndigital signals\nand stored on hard drives together with the time signals provided by the atomic clock. The hard drives are then shipped to a central location to be synchronized. An astronomical observation image is obtained by processing the data gathered from multiple locations.\nEHT observations during its 2017 M87 multiwavelength campaign decomposed by instrument from lower (EHT\/ALMA\/SMA) to higher (VERITAS) frequency. (Fermi-LAT in continuous survey mode) (dates also in\nModified Julian days\n)\nSoft\nX-ray\nimage of\nSagittarius A*\n(center) and two\nlight echoes\nfrom a recent explosion (circled)\nThe EHT is composed of many radio observatories or radio-telescope facilities around the world, working together to produce a high-sensitivity, high-angular-resolution telescope. Through the technique of\nvery-long-baseline interferometry\n(VLBI), many independent radio antennas separated by hundreds or thousands of kilometres can act as a\nphased array\n, a virtual telescope which can be pointed electronically, with an\neffective aperture\nwhich is the diameter of the entire planet, substantially improving its angular resolution.\n[\n17\n]\nThe effort includes development and deployment of\nsubmillimeter\ndual\npolarization\nreceivers, highly stable frequency standards to enable very-long-baseline interferometry at 230–450 GHz, higher-bandwidth VLBI backends and recorders, as well as commissioning of new submillimeter VLBI sites.\n[\n18\n]\nEach year since its first data capture in 2006, the EHT array has moved to add more observatories to its global network of radio telescopes. The first image of the Milky Way's supermassive black hole, Sagittarius A*, was expected to be produced from data taken in April 2017,\n[\n19\n]\n[\n20\n]\nbut because there are no flights in or out of the South Pole during austral winter (April to October), the full data set could not be processed until December 2017, when the shipment of data from the\nSouth Pole Telescope\narrived.\n[\n21\n]\nData collected on hard drives are transported by commercial freight airplanes\n[\n22\n]\n(a so-called\nsneakernet\n) from the various telescopes to the\nMIT\nHaystack Observatory\nand the\nMax Planck Institute for Radio Astronomy\n, where the data are\ncross-correlated\nand analyzed on a\ngrid computer\nmade from about 800\nCPUs\nall connected through a\n40 Gbit\/s\nnetwork.\n[\n23\n]\nBecause of the\nCOVID-19 pandemic\n, weather patterns, and celestial mechanics, the 2020 observational campaign was postponed to March 2021.\n[\n24\n]\nA series of images descriptive of the level of magnification achieved by the EHT (akin to seeing, from the Earth's surface, an object the size of a tennis ball on the Moon); starts at top-left image and moves counter−clockwise to finish at top-right corner\nImage of\nM87*\ngenerated from data gathered by the Event Horizon Telescope\n[\n25\n]\n[\n26\n]\nA view of\nM87*\nblack hole in polarised light\nThe Event Horizon Telescope Collaboration announced its first results in six simultaneous press conferences worldwide on April 10, 2019.\n[\n25\n]\n[\n26\n]\n[\n27\n]\nThe announcement featured the first direct image of a black hole, which showed the\nsupermassive black hole\nat the center of\nMessier 87\n, designated M87*.\n[\n2\n]\n[\n28\n]\n[\n29\n]\nThe scientific results were presented in a series of six papers published in\nThe Astrophysical Journal Letters\n.\n[\n30\n]\nA clockwise\nrotating black hole\nwas observed in the 6σ region.\n[\n31\n]\nThe image provided a test for\nAlbert Einstein\n's\ngeneral theory of relativity\nunder extreme conditions.\n[\n17\n]\n[\n20\n]\nStudies have previously tested general relativity by looking at the motions of stars and gas clouds near the edge of a black hole. However, an image of a black hole brings observations even closer to the event horizon.\n[\n32\n]\nRelativity predicts a dark shadow-like region, caused by gravitational bending and capture of light,\n[\n5\n]\n[\n6\n]\nwhich matches the observed image. The published paper states: \"Overall, the observed image is consistent with expectations for the shadow of a\nspinning Kerr black hole\nas predicted by general relativity.\"\n[\n33\n]\nPaul T. P. Ho, EHT Board member, said: \"Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter, and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well.\"\n[\n30\n]\nThe image also provided new measurements for the mass and diameter of M87*. EHT measured the black hole's mass to be\n6.5\n±\n0.7 billion\nsolar masses\nand measured the diameter of its event horizon to be approximately 40 billion kilometres (270 AU; 0.0013 pc; 0.0042 ly), roughly 2.5 times smaller than the shadow that it casts, seen at the center of the image.\n[\n30\n]\n[\n32\n]\nPrevious observations of M87 showed that the large-scale\njet\nis inclined at an angle of 17° relative to the observer's line of sight and oriented on the plane of the sky at a\nposition angle\nof −72°.\n[\n2\n]\n[\n34\n]\nFrom the enhanced brightness of the southern part of the ring due to\nrelativistic beaming\nof approaching funnel wall jet emission, EHT concluded the black hole, which anchors the jet, spins clockwise, as seen from Earth.\n[\n2\n]\n[\n14\n]\nEHT simulations allow for both prograde and retrograde inner disk rotation with respect to the black hole, while excluding zero black hole spin using a conservative minimum jet power of 10\n42\nerg\/s via the\nBlandford–Znajek process\n.\n[\n2\n]\n[\n35\n]\nProducing an image from data from an array of radio telescopes requires much mathematical work. Four independent teams created images to assess the reliability of the results.\n[\n36\n]\nThese methods included both an established algorithm in\nradio astronomy\nfor\nimage reconstruction\nknown as\nCLEAN\n, invented by\nJan Högbom\n,\n[\n37\n]\nas well as self-calibrating\nimage processing\nmethods\n[\n38\n]\nfor astronomy such as the\nCHIRP algorithm\ncreated by\nKatherine Bouman\nand others.\n[\n36\n]\n[\n39\n]\nThe algorithms that were ultimately used were a\nregularized\nmaximum likelihood\n(RML)\n[\n40\n]\nalgorithm and the\nCLEAN\nalgorithm.\n[\n36\n]\nIn March 2020, astronomers proposed an improved way of seeing more of the rings in the first black hole image.\n[\n41\n]\n[\n42\n]\nIn March 2021, a new photo was revealed, showing how the M87 black hole looks in polarised light. This is the first time astronomers have been able to measure polarisation so close to the edge of a black hole. The lines on the photo mark the orientation of polarisation, which is related to the magnetic field around the shadow of the black hole.\n[\n43\n]\nIn August 2022, a team led by\nUniversity of Waterloo\nresearcher Avery Broderick released a \"remaster[ed]\" version of original image generated from the data collected by the EHT. This image \"resolve[d] a fundamental signature of gravity around a black hole\", with it showing a displaying\nphoton ring\naround\nM87*\n.\n[\n44\n]\n[\n45\n]\nThe claim has been subsequently disputed.\n[\n46\n]\nIn 2023, EHT released new, sharper images of the M87 black hole, reconstructed from the same 2017 data but created using the PRIMO algorithm.\n[\n47\n]\nEHT image of the archetypal blazar 3C 279 showing a relativistic jet down to the AGN core surrounding the supermassive black hole.\nIn April 2020, the EHT released the first 20 microarcsecond resolution images of the archetypal\nblazar\n3C 279\nit observed in April 2017.\n[\n48\n]\nThese images, generated from observations over 4 nights in April 2017, reveal bright components of a jet whose projection on the observer plane exhibit apparent\nsuperluminal motions\nwith speeds up to 20 \nc\n.\n[\n49\n]\nSuch apparent superluminal motion from relativistic emitters such as an approaching jet is explained by emission originating closer to the observer (downstream along the jet) catching up with emission originating further from the observer (at the jet base) as the jet propagates close to the speed of light at small angles to the line of sight.\nImage of Centaurus A showing its black hole jet at different scales\nIn July 2021, high resolution images of the jet produced by a supermassive black hole sitting at the center of\nCentaurus A\nwere released. With a mass around\n5.5\n×\n10\n7\n \nM\n☉\n, the black hole is not large enough for its\nphoton sphere\nto be observed, as in EHT images of Messier M87*, but its jet extends even beyond its host galaxy while staying as a highly collimated beam which is a point of study. Edge-brightening of the jet was also observed which would exclude models of particle acceleration that are unable to reproduce this effect. The image was 16 times sharper than previous observations and utilized a 1.3 mm wavelength.\n[\n50\n]\n[\n51\n]\n[\n52\n]\nSagittarius A* in polarised light, image released in 2024\nOn May 12, 2022, the EHT Collaboration revealed an image of\nSagittarius A*\n, the supermassive black hole at the\ncenter\nof the\nMilky Way\ngalaxy\n. The black hole is 27,000 light-years away from Earth; it is thousands of times smaller than M87*.\nSera Markoff\n, Co-Chair of the EHT Science Council, said: \"We have two completely different types of galaxies and two very different black hole masses, but close to the edge of these black holes they look amazingly similar. This tells us that General Relativity governs these objects up close, and any differences we see further away must be due to differences in the material that surrounds the black holes.\"\n[\n53\n]\nOn March 22, 2024, the EHT Collaboration released an image of Sagittarius A* in polarized light.\n[\n54\n]\nA multifrequency view of the bent jet in Blazar J1924-2914.\n[\n55\n]\n[\n56\n]\nIn August 2022, the EHT together with Global Millimeter VLBI Array and the\nVery Long Baseline Array\nimaged the distant\nblazar\nJ1924-2914. They operated at 230 GHz, 86 GHz and 2.3+8.7 GHz, respectively, the highest angular resolution images of polarized emission from a quasar ever obtained. Observations reveal a helically bent jet and the polarization of its emission suggest a toroidal magnetic field structure. The object is used as calibrator for Sagittarius A* sharing strong optical variability and polarization with it.\n[\n55\n]\n[\n56\n]\nNRAO 530 by EHT. The total intensity is shown in grayscale with black contours indicating 10%, 25%, 50%, and 75% of the peak LP intensity. Black dotted contours indicate 25%, 50%, and 75% of the peak polarized intensity.\nSchematic of the total-intensity and LP components in the EHT fiducial image of NRAO 530; white contours show the total intensity levels; color scale and cyan contours represent the polarized intensity of the method-averaged image.\nIn February 2023, the EHT reported on the observations of the\nquasar\nNRAO 530. NRAO 530 (1730−130, J1733−1304) is a\nflat-spectrum radio quasar\n(FSRQ) that belongs to the class of bright γ-ray\nblazars\nand shows significant variability across the entire electromagnetic spectrum. The source was monitored by the University of Michigan Radio Observatory at 4.8, 8.4, and 14.5 GHz for several decades until 2012. The quasar underwent a dramatic radio outburst in 1997, during which its flux density at 14.5 GHz exceeded 10 Jy, while the average value is ~2 Jy. Since 2002, NRAO 530 has been monitored by the Submillimeter Array (SMA; Maunakea, Hawaii) at 1.3 mm and 870 μm. NRAO 530 has a redshift of\nz\n= 0.902 (Junkkarinen 1984), for which 100 μas corresponds to a linear distance of 6 billion pc. The source contains a supermassive black hole, the mass of which is currently uncertain, with estimates ranging from\n3\n×\n10\n8\n \nM\n☉\nto\n2\n×\n10\n9\n \nM\n☉\n.\n[\n57\n]\nIt was observed with the Event Horizon Telescope on April 5−7, 2017, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A*. The observations were performed with the full EHT 2017 array of eight telescopes located at six geographical sites. At\nz\n= 0.902, this is the most distant object imaged by the EHT so far. The team reconstructed the first images of the source at 230 GHz, at an angular resolution of about 20 μas, both in total intensity and in linear polarization (LP). Source variability was not detected, that allowed to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which was associated with the core. The feature is linearly polarized, with a fractional polarization of about 5%–8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle about −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field.\n[\n57\n]\nCollaborating institutes\n[\nedit\n]\nThe EHT Collaboration consists of 13 stakeholder institutes:\n[\n58\n]\nthe\nAcademia Sinica\nInstitute of Astronomy and Astrophysics\nthe\nUniversity of Arizona\nthe\nUniversity of Chicago\nthe\nEast Asian Observatory\nGoethe University Frankfurt\nSmithsonian Astrophysical Observatory\n(part of the\nHarvard–Smithsonian Center for Astrophysics\n)\nInstitut de radioastronomie millimétrique\n(IRAM, itself a collaboration between the French\nCNRS\n, the German\nMax Planck Society\n, and the Spanish\nInstituto Geográfico Nacional\n)\nLarge Millimeter Telescope\nAlfonso Serrano\nMax Planck Institute for Radio Astronomy\nMIT\nHaystack Observatory\nNational Astronomical Observatory of Japan\nPerimeter Institute for Theoretical Physics\nRadboud University\nLocations of the telescopes that make up the EHT array. A global map showing the radio observatories that form the Event Horizon Telescope (EHT) network used to image the Milky Way's central black hole, Sagittarius A*. The telescopes highlighted in yellow were part of the EHT network during the observations of Sagittarius A* in 2017. These include the Atacama Large Millimeter\/submillimeter Array (ALMA), the Atacama Pathfinder EXperiment (APEX), IRAM 30-meter telescope (30-M), James Clark Maxwell Telescope (JCMT), Large Millimeter Telescope (LMT), Submillimeter Array (SMA), Submillimetere Telescope (SMT) and South Pole Telescope (SPT). Highlighted in blue are the three telescopes added to the EHT Collaboration after 2018: the Greenland Telescope (GLT), the NOrthern Extended Millimeter Array (NOEMA) in France, and the University of Arizona ARO 12-meter Telescope at Kitt Peak.\nThe EHT Collaboration receives funding from numerous sources including:\n[\n59\n]\nUnited States National Science Foundation\nEuropean Research Council\nNational Science and Technology Council of Taiwan\n(formerly Ministry of Science and Technology of Taiwan)\nMax Planck Society\nConsejo Nacional de Ciencia y Technologia, Mexico\nJohn Templeton Foundation\nGordon and Betty Moore Foundation\nJapan Society for the Promotion of Science\nNatural Sciences and Engineering Research Council of Canada\nAcademia Sinica\nSmithsonian Institution\nAdditionally,\nWestern Digital\nand\nXilinx\nare industry donors.\n[\n60\n]\n^\na\nb\nDoeleman, Sheperd (June 21, 2009). \"Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole\".\nAstro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers\n.\n2010\n: 68.\narXiv\n:\n0906.3899\n.\nBibcode\n:\n2009astro2010S..68D\n.\n^\na\nb\nc\nd\ne\nf\nThe Event Horizon Telescope Collaboration (April 10, 2019).\n\"First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole\"\n.\nThe Astrophysical Journal Letters\n.\n875\n(1): L1.\narXiv\n:\n1906.11238\n.\nBibcode\n:\n2019ApJ...875L...1E\n.\ndoi\n:\n10.3847\/2041-8213\/ab0ec7\n.\nS2CID\n \n145906806\n.\n^\nBardeen, James (1973). \"Black holes. Edited by C. DeWitt and B. S. DeWitt\".\nLes Houches École d'Été de Physique Théorique\n.\nBibcode\n:\n1973blho.conf.....D\n.\n^\nLuminet, Jean-Pierre (July 31, 1979). \"Image of a spherical black hole with thin accretion disk\".\nAstronomy and Astrophysics\n.\n75\n: 228.\nBibcode\n:\n1979A&A....75..228L\n.\n^\na\nb\nFalcke, Heino; Melia, Fulvio; Agol, Eric (January 1, 2000). \"Viewing the Shadow of the Black Hole at the Galactic Center\".\nThe Astrophysical Journal Letters\n.\n528\n(1):\nL13–\nL16.\narXiv\n:\nastro-ph\/9912263\n.\nBibcode\n:\n2000ApJ...528L..13F\n.\ndoi\n:\n10.1086\/312423\n.\nPMID\n \n10587484\n.\nS2CID\n \n119433133\n.\n^\na\nb\nBroderick, Avery; Loeb, Abraham (April 11, 2006).\n\"Imaging optically-thin hotspots near the black hole horizon of Sgr A* at radio and near-infrared wavelengths\"\n.\nMonthly Notices of the Royal Astronomical Society\n.\n367\n(3):\n905–\n916.\narXiv\n:\nastro-ph\/0509237\n.\nBibcode\n:\n2006MNRAS.367..905B\n.\ndoi\n:\n10.1111\/j.1365-2966.2006.10152.x\n.\nS2CID\n \n16881360\n.\n^\nBalick, Bruce; Brown, R.L. (December 1, 1974).\n\"Intense sub-arcsecond structure in the galactic center\"\n.\nThe Astrophysical Journal\n.\n194\n(1):\n265–\n279.\nBibcode\n:\n1974ApJ...194..265B\n.\ndoi\n:\n10.1086\/153242\n.\nS2CID\n \n121802758\n.\n^\nDoeleman, Sheperd (September 4, 2008). \"Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre\".\nNature\n.\n455\n(7209):\n78–\n80.\narXiv\n:\n0809.2442\n.\nBibcode\n:\n2008Natur.455...78D\n.\ndoi\n:\n10.1038\/nature07245\n.\nPMID\n \n18769434\n.\nS2CID\n \n4424735\n.\n^\nDoeleman, Sheperd (October 19, 2012). \"Jet-launching structure resolved near the supermassive black hole in M87\".\nScience\n.\n338\n(6105):\n355–\n358.\narXiv\n:\n1210.6132\n.\nBibcode\n:\n2012Sci...338..355D\n.\ndoi\n:\n10.1126\/science.1224768\n.\nPMID\n \n23019611\n.\nS2CID\n \n37585603\n.\n^\n\"Winners Of The 2020 Breakthrough Prize In Life Sciences, Fundamental Physics And Mathematics Announced\"\n.\nBreakthrough Prize\n. Retrieved\nMarch 15,\n2020\n.\n^\n\"Event Horizon Telescope 2022\"\n. March 12, 2022.\n^\nShep Doeleman, on behalf of the EHT Collaboration (April 2019).\n\"Focus on the First Event Horizon Telescope Results\"\n.\nThe Astrophysical Journal Letters\n. Retrieved\nApril 10,\n2019\n.\n^\nOverbye, Dennis\n(March 24, 2021).\n\"The Most Intimate Portrait Yet of a Black Hole – Two years of analyzing the polarized light from a galaxy's giant black hole has given scientists a glimpse at how quasars might arise\"\n.\nThe New York Times\n. Retrieved\nMarch 25,\n2021\n.\n^\na\nb\nKohler, Susanna (April 10, 2019).\n\"First Images of a Black Hole from the Event Horizon Telescope\"\n. AAS Nova\n. Retrieved\nApril 10,\n2019\n.\n^\nOverbye, Dennis\n(May 12, 2022).\n\"Has the Milky Way's Black Hole Come to Light? – The Event Horizon Telescope reaches again for a glimpse of the 'unseeable'\n\"\n.\nThe New York Times\n. Retrieved\nMay 12,\n2022\n.\n^\nAlexander W. Raymond et al 2024 AJ 168 130\n^\na\nb\nO'Neill, Ian (July 2, 2015).\n\"Event Horizon Telescope Will Probe Spacetime's Mysteries\"\n.\nDiscovery News\n. Archived from\nthe original\non September 5, 2015\n. Retrieved\nAugust 21,\n2015\n.\n^\n\"MIT Haystack Observatory: Astronomy Wideband VLBI Millimeter Wavelength\"\n.\nwww.haystack.mit.edu\n.\n^\nWebb, Jonathan (January 8, 2016).\n\"Event horizon snapshot due in 2017\"\n.\nBBC News\n. Retrieved\nMarch 24,\n2016\n.\n^\na\nb\nDavide Castelvecchi (March 23, 2017).\n\"How to hunt for a black hole with a telescope the size of Earth\"\n.\nNature\n.\n543\n(7646):\n478–\n480.\nBibcode\n:\n2017Natur.543..478C\n.\ndoi\n:\n10.1038\/543478a\n.\nPMID\n \n28332538\n.\n^\n\"EHT Status Update, December 15 2017\"\n.\neventhorizontelescope.org\n. December 15, 2017\n. Retrieved\nFebruary 9,\n2018\n.\n^\n\"The Hidden Shipping and Handling Behind That Black-Hole Picture\"\n.\nThe Atlantic\n. April 13, 2019\n. Retrieved\nApril 14,\n2019\n.\n^\nMearian, Lucas (August 18, 2015).\n\"Massive telescope array aims for black hole, gets gusher of data\"\n.\nComputerworld\n. Retrieved\nAugust 21,\n2015\n.\n^\n\"EHT Observing Campaign 2020 Canceled Due to the COVID-19 Outbreak\"\n.\neventhorizontelescope.org\n. March 17, 2020\n. Retrieved\nMarch 29,\n2020\n.\n^\na\nb\nOverbye, Dennis\n(April 10, 2019).\n\"Black Hole Picture Revealed for the First Time\"\n.\nThe New York Times\n. Retrieved\nApril 10,\n2019\n.\n^\na\nb\nLandau, Elizabeth (April 10, 2019).\n\"Black Hole Image Makes History\"\n.\nNASA\n. Retrieved\nApril 10,\n2019\n.\n^\n\"Media Advisory: First Results from the Event Horizon Telescope to be Presented on April 10th\"\n.\nEvent Horizon official blog\n. Event Horizon Telescope. April 1, 2019\n. Retrieved\nApril 10,\n2019\n.\n^\nLu, Donna (April 12, 2019).\n\"How do you name a black hole? It is actually pretty complicated\"\n.\nNew Scientist\n. London\n. Retrieved\nApril 12,\n2019\n.\n'For the case of M87*, which is the designation of this black hole, a (very nice) name has been proposed, but it has not received an official IAU approval,' says Christensen.\n^\nGardiner, Aidan (April 12, 2018).\n\"When a Black Hole Finally Reveals Itself, It Helps to Have Our Very Own Cosmic Reporter\"\n.\nThe New York Times\n. Retrieved\nApril 15,\n2019\n.\n^\na\nb\nc\n\"Astronomers Capture First Image of a Black Hole\"\n.\nEuropean Southern Observatory\n. April 10, 2019\n. Retrieved\nApril 10,\n2019\n.\n^\nTamburini, Fabrizio; Thidé, Bo; Della Valle, Massimo (2020).\n\"Measurement of the spin of the M87 black hole from its observed twisted light\"\n.\nMonthly Notices of the Royal Astronomical Society: Letters\n.\n492\n:\nL22–\nL27.\narXiv\n:\n1904.07923\n.\ndoi\n:\n10.1093\/mnrasl\/slz176\n.\n^\na\nb\nGrossman, Lisa; Conover, Emily (April 10, 2019).\n\"The first picture of a black hole opens a new era of astrophysics\"\n.\nScience News\n. Retrieved\nApril 10,\n2019\n.\n^\nJake Parks (April 10, 2019).\n\"The nature of M87: EHT's look at a supermassive black hole\"\n.\nAstronomy\n. Retrieved\nApril 10,\n2019\n.\n^\nWalker, R. Craig; Hardee, Philip E.; Davies, Frederick B.; Ly, Chun; Junor, William (2018).\n\"The Structure and Dynamics of the Subparsec Jet in M87 Based on 50 VLBA Observations over 17 Years at 43 GHZ\"\n.\nThe Astrophysical Journal\n.\n855\n(2): 128.\narXiv\n:\n1802.06166\n.\nBibcode\n:\n2018ApJ...855..128W\n.\ndoi\n:\n10.3847\/1538-4357\/aaafcc\n.\nS2CID\n \n59322635\n.\n^\nBlandford, R. D.; Znajek, R. L. (1977).\n\"Electromagnetic extraction of energy from Kerr black holes\"\n.\nMonthly Notices of the Royal Astronomical Society\n.\n179\n(3): 433.\nBibcode\n:\n1977MNRAS.179..433B\n.\ndoi\n:\n10.1093\/mnras\/179.3.433\n.\n^\na\nb\nc\nThe Event Horizon Telescope Collaboration (2019).\n\"First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole\"\n.\nAstrophysical Journal Letters\n.\n87\n(1): L4.\narXiv\n:\n1906.11241\n.\nBibcode\n:\n2019ApJ...875L...4E\n.\ndoi\n:\n10.3847\/2041-8213\/ab0e85\n.\nS2CID\n \n146068771\n.\n^\nHögbom, Jan A. (1974). \"Aperture Synthesis with a Non-Regular Distribution of Interferometer Baselines\".\nAstronomy and Astrophysics Supplement\n.\n15\n:\n417–\n426.\nBibcode\n:\n1974A&AS...15..417H\n.\n^\nSeitz, Stella; Schneider, Peter; Bartelmann, Matthias (1998). \"Entropy-regularized maximum-likelihood cluster mass reconstruction\".\nAstronomy and Astrophysics\n.\n337\n: 325.\narXiv\n:\nastro-ph\/9803038\n.\nBibcode\n:\n1998A&A...337..325S\n.\n^\nShu, Catherine (April 11, 2019).\n\"The creation of the algorithm that made the first black hole image possible was led by MIT grad student Katie Bouman\"\n.\nTechCrunch\n. Retrieved\nApril 15,\n2019\n.\n^\nNarayan, Ramesh; Nityananda, Rajaram (1986). \"Maximum Entropy Image Restoration in Astronomy\".\nAnnual Review of Astronomy and Astrophysics\n.\n24\n:\n127–\n170.\nBibcode\n:\n1986ARA&A..24..127N\n.\ndoi\n:\n10.1146\/annurev.aa.24.090186.001015\n.\n^\nOverbye, Dennis\n(March 28, 2020).\n\"Infinite Visions Were Hiding in the First Black Hole Image's Rings\"\n.\nThe New York Times\n. Retrieved\nMarch 29,\n2020\n.\n^\nJohnson, Michael D.; et al. (March 18, 2020).\n\"Universal interferometric signatures of a black hole's photon ring\"\n.\nScience Advances\n.\n6\n(12, eaaz1310) eaaz1310.\narXiv\n:\n1907.04329\n.\nBibcode\n:\n2020SciA....6.1310J\n.\ndoi\n:\n10.1126\/sciadv.aaz1310\n.\nPMC\n \n7080443\n.\nPMID\n \n32206723\n.\n^\n\"A view of the M87 supermassive black hole in polarised light\"\n. ESO\n. Retrieved\nMarch 24,\n2021\n.\n^\n\"The photon ring: a black hole ready for its close-up\"\n.\nWaterloo News\n. August 16, 2022\n. Retrieved\nAugust 28,\n2022\n.\n^\nLea, Robert (August 17, 2022).\n\"Supermassive black hole's bright 'photon ring' revealed in new image\"\n.\nSpace.com\n. Retrieved\nAugust 28,\n2022\n.\n^\n\"Physicists dispute a claim of detecting a black hole's 'photon ring'\n\"\n.\nScience News\n. August 31, 2022\n. Retrieved\nSeptember 19,\n2022\n.\n^\nMedeiros, Lia; Psaltis, Dimitrios; Lauer, Tod R.; Özel, Feryal (April 1, 2023).\n\"The Image of the M87 Black Hole Reconstructed with PRIMO\"\n.\nThe Astrophysical Journal Letters\n.\n947\n(1): L7.\narXiv\n:\n2304.06079\n.\nBibcode\n:\n2023ApJ...947L...7M\n.\ndoi\n:\n10.3847\/2041-8213\/acc32d\n.\nS2CID\n \n258108405\n.\n^\nKim, Jae-Young; et al. (April 5, 2020).\n\"Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution\"\n.\nAstronomy & Astrophysics\n.\n640\n: A69.\nBibcode\n:\n2020A&A...640A..69K\n.\ndoi\n:\n10.1051\/0004-6361\/202037493\n.\nhdl\n:\n10261\/227201\n.\n^\n\"Something is Lurking in the Heart of Quasar 3C 279\"\n.\nEvent Horizon Telescope\n. Retrieved\nApril 20,\n2019\n.\n^\nJanssen, Michael; Falcke, Heino; Kadler, Matthias; Ros, Eduardo; Wielgus, Maciek; Akiyama, Kazunori; et al. (July 19, 2021).\n\"Event Horizon Telescope observations of the jet launching and collimation in Centaurus A\"\n.\nNature Astronomy\n.\n5\n(10):\n1017–\n1028.\narXiv\n:\n2111.03356\n.\nBibcode\n:\n2021NatAs...5.1017J\n.\ndoi\n:\n10.1038\/s41550-021-01417-w\n.\nISSN\n \n2397-3366\n.\n^\nGabuzda, Denise C. (July 19, 2021). \"Peering into the heart of an active galaxy\".\nNature Astronomy\n.\n5\n(10):\n982–\n983.\nBibcode\n:\n2021NatAs...5..982G\n.\ndoi\n:\n10.1038\/s41550-021-01420-1\n.\nISSN\n \n2397-3366\n.\nS2CID\n \n237675257\n.\n^\n\"EHT Pinpoints Dark Heart of the Nearest Radio Galaxy\"\n. Event Horizon Telescope. July 19, 2021\n. Retrieved\nJuly 20,\n2021\n.\n^\n\"Astronomers reveal first image of the black hole at the heart of our galaxy\"\n(Press release). ESO. May 12, 2022.\n^\n\"Astronomers unveil strong magnetic fields spiraling at the edge of Milky Way's central black hole\"\n.\nESO\n. Retrieved\nMarch 27,\n2024\n.\n^\na\nb\nIssaoun, Sara; Wielgus, Maciek; Jorstad, Svetlana; Krichbaum, Thomas P.; Blackburn, Lindy; Janssen, Michael; Chan, Chi-kwan; Pesce, Dominic W.; Gómez, José L.; Akiyama, Kazunori; Mościbrodzka, Monika; Martí-Vidal, Iván; Chael, Andrew; Lico, Rocco; Liu, Jun (August 1, 2022).\n\"Resolving the Inner Parsec of the Blazar J1924–2914 with the Event Horizon Telescope\"\n.\nThe Astrophysical Journal\n.\n934\n(2): 145.\narXiv\n:\n2208.01662\n.\nBibcode\n:\n2022ApJ...934..145I\n.\ndoi\n:\n10.3847\/1538-4357\/ac7a40\n.\nISSN\n \n0004-637X\n.\nS2CID\n \n251274752\n.\n^\na\nb\n\"Resolving the core of the J1924-2914 blazar with the Event Horizon Telescope\"\n.\nEvent Horizon Telescope\n. August 6, 2022\n. Retrieved\nAugust 14,\n2022\n.\n^\na\nb\nJorstad, Svetlana; et al. (February 1, 2023).\n\"The Event Horizon Telescope Image of the Quasar NRAO 530\"\n.\nThe Astrophysical Journal\n.\n943\n(2): 170.\narXiv\n:\n2302.04622\n.\nBibcode\n:\n2023ApJ...943..170J\n.\ndoi\n:\n10.3847\/1538-4357\/acaea8\n.\nS2CID\n \n256661718\n.\nMaterial was copied from this source, which is available under a\nCreative Commons Attribution 4.0\n.\n^\nEvent Horizon Telescopoe, Organisation\n, EHT Website, accessed: 2022-01-30.\n^\n\"Funding Support\"\n.\neventhorizontelescope.org\n. Retrieved\nSeptember 27,\n2023\n.\n^\n\"Industry Donors\"\n.\neventhorizontelescope.org\n. Retrieved\nSeptember 27,\n2023\n.\nOfficial website\nEHT \"Ask Me Anything\" (AMA) serie\non\nreddit\nThe Next Generation Event Horizon Telescope","attrs_markdown":"[Jump to content](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#bodyContent)\n\nMain menu\n\nMain menu\n\nmove to sidebar\n\nhide\n\nNavigation\n\n- [Main page](https:\/\/en.wikipedia.org\/wiki\/Main_Page \"Visit the main page [z]\")\n- [Contents](https:\/\/en.wikipedia.org\/wiki\/Wikipedia:Contents \"Guides to browsing Wikipedia\")\n- [Current events](https:\/\/en.wikipedia.org\/wiki\/Portal:Current_events \"Articles related to current events\")\n- [Random article](https:\/\/en.wikipedia.org\/wiki\/Special:Random \"Visit a randomly selected article [x]\")\n- [About Wikipedia](https:\/\/en.wikipedia.org\/wiki\/Wikipedia:About \"Learn about Wikipedia and how it works\")\n- [Contact us](https:\/\/en.wikipedia.org\/wiki\/Wikipedia:Contact_us \"How to contact Wikipedia\")\n\nContribute\n\n- [Help](https:\/\/en.wikipedia.org\/wiki\/Help:Contents \"Guidance on how to use and edit Wikipedia\")\n- [Learn to edit](https:\/\/en.wikipedia.org\/wiki\/Help:Introduction \"Learn how to edit Wikipedia\")\n- [Community portal](https:\/\/en.wikipedia.org\/wiki\/Wikipedia:Community_portal \"The hub for editors\")\n- [Recent changes](https:\/\/en.wikipedia.org\/wiki\/Special:RecentChanges \"A list of recent changes to Wikipedia [r]\")\n- [Upload file](https:\/\/en.wikipedia.org\/wiki\/Wikipedia:File_upload_wizard \"Add images or other media for use on Wikipedia\")\n- [Special pages](https:\/\/en.wikipedia.org\/wiki\/Special:SpecialPages \"A list of all special pages [q]\")\n\n[![](https:\/\/en.wikipedia.org\/static\/images\/icons\/enwiki-25.svg) ![Wikipedia](https:\/\/en.wikipedia.org\/static\/images\/mobile\/copyright\/wikipedia-wordmark-en-25.svg) ![The Free Encyclopedia](https:\/\/en.wikipedia.org\/static\/images\/mobile\/copyright\/wikipedia-tagline-en-25.svg)](https:\/\/en.wikipedia.org\/wiki\/Main_Page)\n\n[Search](https:\/\/en.wikipedia.org\/wiki\/Special:Search \"Search Wikipedia [f]\")\n\nAppearance\n\n- [Donate](https:\/\/donate.wikimedia.org\/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en)\n- [Create account](https:\/\/en.wikipedia.org\/w\/index.php?title=Special:CreateAccount&returnto=Event+Horizon+Telescope \"You are encouraged to create an account and log in; however, it is not mandatory\")\n- [Log in](https:\/\/en.wikipedia.org\/w\/index.php?title=Special:UserLogin&returnto=Event+Horizon+Telescope \"You're encouraged to log in; however, it's not mandatory. [o]\")\n\nPersonal tools\n\n- [Donate](https:\/\/donate.wikimedia.org\/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en)\n- [Create account](https:\/\/en.wikipedia.org\/w\/index.php?title=Special:CreateAccount&returnto=Event+Horizon+Telescope \"You are encouraged to create an account and log in; however, it is not mandatory\")\n- [Log in](https:\/\/en.wikipedia.org\/w\/index.php?title=Special:UserLogin&returnto=Event+Horizon+Telescope \"You're encouraged to log in; however, it's not mandatory. [o]\")\n\n## Contents\nmove to sidebar\n\nhide\n\n- [(Top)](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope)\n- [1 Telescope array](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#Telescope_array)\n- [2 Published images](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#Published_images)\n  Toggle Published images subsection\n  - [2\\.1 Messier 87\\*](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#Messier_87*)\n  - [2\\.2 3C 279](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#3C_279)\n  - [2\\.3 Centaurus A](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#Centaurus_A)\n  - [2\\.4 Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#Sagittarius_A*)\n  - [2\\.5 J1924-2914](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#J1924-2914)\n  - [2\\.6 NRAO 530](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#NRAO_530)\n- [3 Collaborating institutes](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#Collaborating_institutes)\n- [4 Funding](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#Funding)\n- [5 References](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#References)\n- [6 External links](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#External_links)\n\nToggle the table of contents\n\n# Event Horizon Telescope\n39 languages\n\n- [العربية](https:\/\/ar.wikipedia.org\/wiki\/%D9%85%D9%82%D8%B1%D8%A7%D8%A8_%D8%A3%D9%81%D9%82_%D8%A7%D9%84%D8%AD%D8%AF%D8%AB \"مقراب أفق الحدث – Arabic\")\n- [অসমীয়া](https:\/\/as.wikipedia.org\/wiki\/%E0%A6%87%E0%A6%AD%E0%A7%87%E0%A6%A3%E0%A7%8D%E0%A6%9F_%E0%A6%B9%27%E0%A7%B0%E0%A6%BE%E0%A6%87%E0%A6%9C%27%E0%A6%A8_%E0%A6%9F%E0%A7%87%E0%A6%B2%E0%A6%BF%E0%A6%B8%E0%A7%8D%E0%A6%95%27%E0%A6%AA \"ইভেণ্ট হ'ৰাইজ'ন টেলিস্ক'প – Assamese\")\n- [Azərbaycanca](https:\/\/az.wikipedia.org\/wiki\/Hadis%C9%99_%C3%9Cf%C3%BCq%C3%BC_Teleskopu \"Hadisə Üfüqü Teleskopu – Azerbaijani\")\n- [বাংলা](https:\/\/bn.wikipedia.org\/wiki\/%E0%A6%87%E0%A6%AD%E0%A7%87%E0%A6%A8%E0%A7%8D%E0%A6%9F_%E0%A6%B9%E0%A6%B0%E0%A6%BE%E0%A6%87%E0%A6%9C%E0%A6%A8_%E0%A6%9F%E0%A7%87%E0%A6%B2%E0%A6%BF%E0%A6%B8%E0%A7%8D%E0%A6%95%E0%A7%8B%E0%A6%AA \"ইভেন্ট হরাইজন টেলিস্কোপ – Bangla\")\n- [Català](https:\/\/ca.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Catalan\")\n- [Čeština](https:\/\/cs.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Czech\")\n- [Cymraeg](https:\/\/cy.wikipedia.org\/wiki\/Telesgop_Event_Horizon \"Telesgop Event Horizon – Welsh\")\n- [Dansk](https:\/\/da.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Danish\")\n- [Deutsch](https:\/\/de.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – German\")\n- [Ελληνικά](https:\/\/el.wikipedia.org\/wiki\/%CE%A4%CE%B7%CE%BB%CE%B5%CF%83%CE%BA%CF%8C%CF%80%CE%B9%CE%BF_%CE%9F%CF%81%CE%AF%CE%B6%CE%BF%CE%BD%CF%84%CE%B1_%CE%93%CE%B5%CE%B3%CE%BF%CE%BD%CF%8C%CF%84%CF%89%CE%BD \"Τηλεσκόπιο Ορίζοντα Γεγονότων – Greek\")\n- [Español](https:\/\/es.wikipedia.org\/wiki\/Telescopio_del_Horizonte_de_Sucesos \"Telescopio del Horizonte de Sucesos – Spanish\")\n- [Euskara](https:\/\/eu.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Basque\")\n- [فارسی](https:\/\/fa.wikipedia.org\/wiki\/%D8%AA%D9%84%D8%B3%DA%A9%D9%88%D9%BE_%D8%A7%D9%81%D9%82_%D8%B1%D9%88%DB%8C%D8%AF%D8%A7%D8%AF \"تلسکوپ افق رویداد – Persian\")\n- [Suomi](https:\/\/fi.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Finnish\")\n- [Français](https:\/\/fr.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – French\")\n- [Galego](https:\/\/gl.wikipedia.org\/wiki\/Telescopio_de_Horizonte_de_Eventos \"Telescopio de Horizonte de Eventos – Galician\")\n- [Magyar](https:\/\/hu.wikipedia.org\/wiki\/Esem%C3%A9nyhorizont_T%C3%A1vcs%C5%91 \"Eseményhorizont Távcső – Hungarian\")\n- [Bahasa Indonesia](https:\/\/id.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Indonesian\")\n- [Italiano](https:\/\/it.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Italian\")\n- [日本語](https:\/\/ja.wikipedia.org\/wiki\/%E3%82%A4%E3%83%99%E3%83%B3%E3%83%88%E3%83%9B%E3%83%A9%E3%82%A4%E3%82%BA%E3%83%B3%E3%83%86%E3%83%AC%E3%82%B9%E3%82%B3%E3%83%BC%E3%83%97 \"イベントホライズンテレスコープ – Japanese\")\n- [한국어](https:\/\/ko.wikipedia.org\/wiki\/%EC%82%AC%EC%83%81%EC%88%98%ED%8F%89%EC%84%A0%EB%A7%9D%EC%9B%90%EA%B2%BD \"사상수평선망원경 – Korean\")\n- [Lietuvių](https:\/\/lt.wikipedia.org\/wiki\/%C4%AEvyki%C5%B3_horizonto_teleskopas \"Įvykių horizonto teleskopas – Lithuanian\")\n- [Bahasa Melayu](https:\/\/ms.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Malay\")\n- [Nederlands](https:\/\/nl.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Dutch\")\n- [Polski](https:\/\/pl.wikipedia.org\/wiki\/Teleskop_Horyzontu_Zdarze%C5%84 \"Teleskop Horyzontu Zdarzeń – Polish\")\n- [Português](https:\/\/pt.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Portuguese\")\n- [Română](https:\/\/ro.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Romanian\")\n- [Русский](https:\/\/ru.wikipedia.org\/wiki\/%D0%A2%D0%B5%D0%BB%D0%B5%D1%81%D0%BA%D0%BE%D0%BF_%D0%B3%D0%BE%D1%80%D0%B8%D0%B7%D0%BE%D0%BD%D1%82%D0%B0_%D1%81%D0%BE%D0%B1%D1%8B%D1%82%D0%B8%D0%B9 \"Телескоп горизонта событий – Russian\")\n- [Slovenčina](https:\/\/sk.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Slovak\")\n- [Српски \/ srpski](https:\/\/sr.wikipedia.org\/wiki\/%D0%A2%D0%B5%D0%BB%D0%B5%D1%81%D0%BA%D0%BE%D0%BF_%D1%85%D0%BE%D1%80%D0%B8%D0%B7%D0%BE%D0%BD%D1%82%D0%B0_%D0%B4%D0%BE%D0%B3%D0%B0%D1%92%D0%B0%D1%98%D0%B0 \"Телескоп хоризонта догађаја – Serbian\")\n- [Svenska](https:\/\/sv.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Swedish\")\n- [ไทย](https:\/\/th.wikipedia.org\/wiki\/%E0%B8%81%E0%B8%A5%E0%B9%89%E0%B8%AD%E0%B8%87%E0%B9%82%E0%B8%97%E0%B8%A3%E0%B8%97%E0%B8%A3%E0%B8%A3%E0%B8%A8%E0%B8%99%E0%B9%8C%E0%B8%82%E0%B8%AD%E0%B8%9A%E0%B8%9F%E0%B9%89%E0%B8%B2%E0%B9%80%E0%B8%AB%E0%B8%95%E0%B8%B8%E0%B8%81%E0%B8%B2%E0%B8%A3%E0%B8%93%E0%B9%8C \"กล้องโทรทรรศน์ขอบฟ้าเหตุการณ์ – Thai\")\n- [Tagalog](https:\/\/tl.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Tagalog\")\n- [Türkçe](https:\/\/tr.wikipedia.org\/wiki\/Olay_Ufku_Teleskobu \"Olay Ufku Teleskobu – Turkish\")\n- [Українська](https:\/\/uk.wikipedia.org\/wiki\/%D0%A2%D0%B5%D0%BB%D0%B5%D1%81%D0%BA%D0%BE%D0%BF_%D0%B3%D0%BE%D1%80%D0%B8%D0%B7%D0%BE%D0%BD%D1%82%D1%83_%D0%BF%D0%BE%D0%B4%D1%96%D0%B9 \"Телескоп горизонту подій – Ukrainian\")\n- [اردو](https:\/\/ur.wikipedia.org\/wiki\/%D8%A7%DB%8C%D9%88%D9%86%D9%B9_%DB%81%D9%88%D8%B1%D8%A7%D8%A6%D8%B2%D9%86_%D9%B9%DB%8C%D9%84%DB%8C_%D8%B3%DA%A9%D9%88%D9%BE \"ایونٹ ہورائزن ٹیلی سکوپ – Urdu\")\n- [Tiếng Việt](https:\/\/vi.wikipedia.org\/wiki\/K%C3%ADnh_thi%C3%AAn_v%C4%83n_Ch%C3%A2n_tr%E1%BB%9Di_s%E1%BB%B1_ki%E1%BB%87n \"Kính thiên văn Chân trời sự kiện – Vietnamese\")\n- [閩南語 \/ Bân-lâm-gí](https:\/\/zh-min-nan.wikipedia.org\/wiki\/Event_Horizon_Telescope \"Event Horizon Telescope – Minnan\")\n- [中文](https:\/\/zh.wikipedia.org\/wiki\/%E4%BA%8B%E4%BB%B6%E8%A6%96%E7%95%8C%E6%9C%9B%E9%81%A0%E9%8F%A1 \"事件視界望遠鏡 – Chinese\")\n\n[Edit links](https:\/\/www.wikidata.org\/wiki\/Special:EntityPage\/Q3944788#sitelinks-wikipedia \"Edit interlanguage links\")\n\n- 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[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/3\/35\/Event_Horizon_Telescope.svg\/250px-Event_Horizon_Telescope.svg.png)](https:\/\/en.wikipedia.org\/wiki\/File:Event_Horizon_Telescope.svg) |   |\n| Alternative names | EHT [![Edit this on Wikidata](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/8\/8a\/OOjs_UI_icon_edit-ltr-progressive.svg\/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https:\/\/www.wikidata.org\/wiki\/Q3944788?uselang=en#P1813 \"Edit this on Wikidata\") |\n| Established | 2009; 17 years ago (2009) |\n| Website | [eventhorizontelescope.org](https:\/\/eventhorizontelescope.org\/) [![Edit this at Wikidata](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/8\/8a\/OOjs_UI_icon_edit-ltr-progressive.svg\/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https:\/\/www.wikidata.org\/wiki\/Q3944788#P856 \"Edit this at Wikidata\") |\n| Telescopes | [Atacama Large Millimeter Array](https:\/\/en.wikipedia.org\/wiki\/Atacama_Large_Millimeter_Array \"Atacama Large Millimeter Array\") [Atacama Pathfinder Experiment](https:\/\/en.wikipedia.org\/wiki\/Atacama_Pathfinder_Experiment \"Atacama Pathfinder Experiment\") [Greenland Telescope](https:\/\/en.wikipedia.org\/wiki\/Greenland_Telescope \"Greenland Telescope\") [Heinrich Hertz Submillimeter Telescope](https:\/\/en.wikipedia.org\/wiki\/Heinrich_Hertz_Submillimeter_Telescope \"Heinrich Hertz Submillimeter Telescope\") [IRAM 30m telescope](https:\/\/en.wikipedia.org\/wiki\/IRAM_30m_telescope \"IRAM 30m telescope\") [James Clerk Maxwell Telescope](https:\/\/en.wikipedia.org\/wiki\/James_Clerk_Maxwell_Telescope \"James Clerk Maxwell Telescope\") [Large Millimeter Telescope](https:\/\/en.wikipedia.org\/wiki\/Large_Millimeter_Telescope \"Large Millimeter Telescope\") [South Pole Telescope](https:\/\/en.wikipedia.org\/wiki\/South_Pole_Telescope \"South Pole Telescope\") [Submillimeter Array](https:\/\/en.wikipedia.org\/wiki\/Submillimeter_Array \"Submillimeter Array\") [![Edit this on Wikidata](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/8\/8a\/OOjs_UI_icon_edit-ltr-progressive.svg\/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https:\/\/www.wikidata.org\/wiki\/Q3944788?uselang=en#P527 \"Edit this on Wikidata\") |\n| [![](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/4\/4a\/Commons-logo.svg\/20px-Commons-logo.svg.png)](https:\/\/en.wikipedia.org\/wiki\/File:Commons-logo.svg) [Related media on Commons](https:\/\/commons.wikimedia.org\/wiki\/Category:Event_Horizon_Telescope \"commons:Category:Event Horizon Telescope\") |   |\n| \\[[edit on Wikidata](https:\/\/www.wikidata.org\/wiki\/Q3944788 \"d:Q3944788\")\\] |   |\n\nThe **Event Horizon Telescope** (**EHT**) is a [telescope array](https:\/\/en.wikipedia.org\/wiki\/Astronomical_interferometer \"Astronomical interferometer\") consisting of a global network of [radio telescopes](https:\/\/en.wikipedia.org\/wiki\/Radio_telescope \"Radio telescope\"). The EHT project combines data from several [very-long-baseline interferometry](https:\/\/en.wikipedia.org\/wiki\/Very-long-baseline_interferometry \"Very-long-baseline interferometry\") (VLBI) stations around Earth, which form a combined array with an [angular resolution](https:\/\/en.wikipedia.org\/wiki\/Angular_resolution \"Angular resolution\") sufficient to observe objects the size of a [supermassive black hole](https:\/\/en.wikipedia.org\/wiki\/Supermassive_black_hole \"Supermassive black hole\")'s [event horizon](https:\/\/en.wikipedia.org\/wiki\/Event_horizon \"Event horizon\"). The project's observational targets include the two [black holes](https:\/\/en.wikipedia.org\/wiki\/Black_hole \"Black hole\") with the largest [angular diameter](https:\/\/en.wikipedia.org\/wiki\/Angular_diameter \"Angular diameter\") as observed from Earth: the black hole at the center of the [supergiant](https:\/\/en.wikipedia.org\/wiki\/Type-cD_galaxy \"Type-cD galaxy\") [elliptical galaxy](https:\/\/en.wikipedia.org\/wiki\/Elliptical_galaxy \"Elliptical galaxy\") [Messier 87](https:\/\/en.wikipedia.org\/wiki\/Messier_87 \"Messier 87\"), and [Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\"), at [the center](https:\/\/en.wikipedia.org\/wiki\/Galactic_Center \"Galactic Center\") of the [Milky Way](https:\/\/en.wikipedia.org\/wiki\/Milky_Way \"Milky Way\").[\\[1\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-wp-2009-1)[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)\n\nThe Event Horizon Telescope project is an international collaboration that was launched in 2009[\\[1\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-wp-2009-1) after a long period of theoretical and technical developments. On the theory side, work on the photon orbit[\\[3\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-3) and first simulations of what a black hole would look like[\\[4\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-4) progressed to predictions of VLBI imaging for the Galactic Center black hole, Sgr A\\*.[\\[5\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:0-5)[\\[6\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:0a-6) Technical advances in radio observing moved from the first detection of Sgr A\\*,[\\[7\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-7) through VLBI at progressively shorter wavelengths, ultimately leading to detection of horizon scale structure in both Sgr A\\* and M87.[\\[8\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-Sheperd2008-8)[\\[9\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-Sheperd2012-9) The collaboration now comprises over 300[\\[10\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-breakthrough-prize-10) members, and 60 institutions, working in over 20 countries and regions.[\\[11\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-website-11)\n\nThe first image of a black hole, at the center of galaxy Messier 87, was published by the EHT Collaboration on April 10, 2019, in a series of six scientific publications.[\\[12\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-apjl-focus-12) The array made this observation at a wavelength of 1.3 mm and with a theoretical [diffraction-limited resolution](https:\/\/en.wikipedia.org\/wiki\/Diffraction-limited_resolution \"Diffraction-limited resolution\") of 25 [microarcseconds](https:\/\/en.wikipedia.org\/wiki\/Microarcsecond \"Microarcsecond\"). In March 2021, the Collaboration presented, for the first time, a [polarized-based image](https:\/\/en.wikipedia.org\/wiki\/Polarization_\\(waves\\) \"Polarization (waves)\") of the [black hole](https:\/\/en.wikipedia.org\/wiki\/Black_hole \"Black hole\") which may help better reveal the forces giving rise to [quasars](https:\/\/en.wikipedia.org\/wiki\/Quasar \"Quasar\").[\\[13\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20210324-13) Future plans involve improving the array's resolution by adding new telescopes and by taking shorter-wavelength observations.[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[14\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-aasnova-20190410-14) On 12 May 2022, astronomers unveiled the first image of the supermassive black hole at the center of the [Milky Way](https:\/\/en.wikipedia.org\/wiki\/Milky_Way \"Milky Way\"), [Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\").[\\[15\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20220512-15) Since 2018 the EHT has been capable of imaging at a wavelength of 870 μm (345 GHz), giving an angular resolution of 19 μas, the best resolution of any ground-based telescope.[\\[16\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-16)\n\n## Telescope array\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=1 \"Edit section: Telescope array\")\\]\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/1\/13\/EHT-infography.png\/250px-EHT-infography.png)](https:\/\/en.wikipedia.org\/wiki\/File:EHT-infography.png)\n\nA schematic diagram of the VLBI mechanism of EHT. Each antenna, spread out over vast distances, has an extremely precise [atomic clock](https:\/\/en.wikipedia.org\/wiki\/Atomic_clock \"Atomic clock\"). [Analogue signals](https:\/\/en.wikipedia.org\/wiki\/Analog_signal \"Analog signal\") collected by the antenna are converted to [digital signals](https:\/\/en.wikipedia.org\/wiki\/Digital_signal \"Digital signal\") and stored on hard drives together with the time signals provided by the atomic clock. The hard drives are then shipped to a central location to be synchronized. An astronomical observation image is obtained by processing the data gathered from multiple locations.\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/2\/23\/EHTobservations2017.jpg\/250px-EHTobservations2017.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:EHTobservations2017.jpg)\n\nEHT observations during its 2017 M87 multiwavelength campaign decomposed by instrument from lower (EHT\/ALMA\/SMA) to higher (VERITAS) frequency. (Fermi-LAT in continuous survey mode) (dates also in [Modified Julian days](https:\/\/en.wikipedia.org\/wiki\/Julian_day#Variants \"Julian day\"))\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/7\/7e\/Sagittarius_A%2A.jpg\/250px-Sagittarius_A%2A.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:Sagittarius_A*.jpg)\n\nSoft [X-ray](https:\/\/en.wikipedia.org\/wiki\/X-ray \"X-ray\") image of [Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\") (center) and two [light echoes](https:\/\/en.wikipedia.org\/wiki\/Light_echo \"Light echo\") from a recent explosion (circled)\n\nThe EHT is composed of many radio observatories or radio-telescope facilities around the world, working together to produce a high-sensitivity, high-angular-resolution telescope. Through the technique of [very-long-baseline interferometry](https:\/\/en.wikipedia.org\/wiki\/Very-long-baseline_interferometry \"Very-long-baseline interferometry\") (VLBI), many independent radio antennas separated by hundreds or thousands of kilometres can act as a [phased array](https:\/\/en.wikipedia.org\/wiki\/Phased_array \"Phased array\"), a virtual telescope which can be pointed electronically, with an [effective aperture](https:\/\/en.wikipedia.org\/wiki\/Aperture_synthesis \"Aperture synthesis\") which is the diameter of the entire planet, substantially improving its angular resolution.[\\[17\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-O'Neil2015-17) The effort includes development and deployment of [submillimeter](https:\/\/en.wikipedia.org\/wiki\/Submillimetre_astronomy \"Submillimetre astronomy\") dual [polarization](https:\/\/en.wikipedia.org\/wiki\/Polarization_\\(waves\\) \"Polarization (waves)\") receivers, highly stable frequency standards to enable very-long-baseline interferometry at 230–450 GHz, higher-bandwidth VLBI backends and recorders, as well as commissioning of new submillimeter VLBI sites.[\\[18\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-18)\n\nEach year since its first data capture in 2006, the EHT array has moved to add more observatories to its global network of radio telescopes. The first image of the Milky Way's supermassive black hole, Sagittarius A\\*, was expected to be produced from data taken in April 2017,[\\[19\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-19)[\\[20\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-nature543-20) but because there are no flights in or out of the South Pole during austral winter (April to October), the full data set could not be processed until December 2017, when the shipment of data from the [South Pole Telescope](https:\/\/en.wikipedia.org\/wiki\/South_Pole_Telescope \"South Pole Telescope\") arrived.[\\[21\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-21)\n\nData collected on hard drives are transported by commercial freight airplanes[\\[22\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-22) (a so-called [sneakernet](https:\/\/en.wikipedia.org\/wiki\/Sneakernet \"Sneakernet\")) from the various telescopes to the [MIT](https:\/\/en.wikipedia.org\/wiki\/MIT \"MIT\") [Haystack Observatory](https:\/\/en.wikipedia.org\/wiki\/Haystack_Observatory \"Haystack Observatory\") and the [Max Planck Institute for Radio Astronomy](https:\/\/en.wikipedia.org\/wiki\/Max_Planck_Institute_for_Radio_Astronomy \"Max Planck Institute for Radio Astronomy\"), where the data are [cross-correlated](https:\/\/en.wikipedia.org\/wiki\/Cross-correlation \"Cross-correlation\") and analyzed on a [grid computer](https:\/\/en.wikipedia.org\/wiki\/Grid_computing \"Grid computing\") made from about 800 [CPUs](https:\/\/en.wikipedia.org\/wiki\/Central_processing_unit \"Central processing unit\") all connected through a 40 Gbit\/s network.[\\[23\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-23)\n\nBecause of the [COVID-19 pandemic](https:\/\/en.wikipedia.org\/wiki\/COVID-19_pandemic \"COVID-19 pandemic\"), weather patterns, and celestial mechanics, the 2020 observational campaign was postponed to March 2021.[\\[24\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-24)\n\n## Published images\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=2 \"Edit section: Published images\")\\]\n\n### Messier 87\\*\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=3 \"Edit section: Messier 87*\")\\]\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/a\/a9\/Event_Horizon_Telescope_and_Apollo_16.png\/250px-Event_Horizon_Telescope_and_Apollo_16.png)](https:\/\/en.wikipedia.org\/wiki\/File:Event_Horizon_Telescope_and_Apollo_16.png)\n\nA series of images descriptive of the level of magnification achieved by the EHT (akin to seeing, from the Earth's surface, an object the size of a tennis ball on the Moon); starts at top-left image and moves counter−clockwise to finish at top-right corner\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/4\/4f\/Black_hole_-_Messier_87_crop_max_res.jpg\/250px-Black_hole_-_Messier_87_crop_max_res.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:Black_hole_-_Messier_87_crop_max_res.jpg)\n\nImage of [M87\\*](https:\/\/en.wikipedia.org\/wiki\/M87* \"M87*\") generated from data gathered by the Event Horizon Telescope[\\[25\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20190410-25)[\\[26\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NASA-20190410-26)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/b\/bf\/A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif\/lossy-page1-250px-A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif)\n\nA view of [M87\\*](https:\/\/en.wikipedia.org\/wiki\/M87* \"M87*\") black hole in polarised light\n\nThe Event Horizon Telescope Collaboration announced its first results in six simultaneous press conferences worldwide on April 10, 2019.[\\[25\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20190410-25)[\\[26\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NASA-20190410-26)[\\[27\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-27) The announcement featured the first direct image of a black hole, which showed the [supermassive black hole](https:\/\/en.wikipedia.org\/wiki\/Supermassive_black_hole \"Supermassive black hole\") at the center of [Messier 87](https:\/\/en.wikipedia.org\/wiki\/Messier_87 \"Messier 87\"), designated M87\\*.[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[28\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NS-name-28)[\\[29\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20190412-29) The scientific results were presented in a series of six papers published in *[The Astrophysical Journal Letters](https:\/\/en.wikipedia.org\/wiki\/The_Astrophysical_Journal_Letters \"The Astrophysical Journal Letters\")*.[\\[30\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eso1907-30) A clockwise [rotating black hole](https:\/\/en.wikipedia.org\/wiki\/Rotating_black_hole \"Rotating black hole\") was observed in the 6σ region.[\\[31\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-RotBlackHole-31)\n\nThe image provided a test for [Albert Einstein](https:\/\/en.wikipedia.org\/wiki\/Albert_Einstein \"Albert Einstein\")'s [general theory of relativity](https:\/\/en.wikipedia.org\/wiki\/General_relativity \"General relativity\") under extreme conditions.[\\[17\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-O'Neil2015-17)[\\[20\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-nature543-20) Studies have previously tested general relativity by looking at the motions of stars and gas clouds near the edge of a black hole. However, an image of a black hole brings observations even closer to the event horizon.[\\[32\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-sciencenews-32) Relativity predicts a dark shadow-like region, caused by gravitational bending and capture of light,[\\[5\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:0-5)[\\[6\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:0a-6) which matches the observed image. The published paper states: \"Overall, the observed image is consistent with expectations for the shadow of a [spinning Kerr black hole](https:\/\/en.wikipedia.org\/wiki\/Spinning_Kerr_black_hole \"Spinning Kerr black hole\") as predicted by general relativity.\"[\\[33\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-33) Paul T. P. Ho, EHT Board member, said: \"Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter, and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well.\"[\\[30\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eso1907-30)\n\nThe image also provided new measurements for the mass and diameter of M87\\*. EHT measured the black hole's mass to be 6\\.5±0\\.7 billion [solar masses](https:\/\/en.wikipedia.org\/wiki\/Solar_masses \"Solar masses\") and measured the diameter of its event horizon to be approximately 40 billion kilometres (270 AU; 0.0013 pc; 0.0042 ly), roughly 2.5 times smaller than the shadow that it casts, seen at the center of the image.[\\[30\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eso1907-30)[\\[32\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-sciencenews-32) Previous observations of M87 showed that the large-scale [jet](https:\/\/en.wikipedia.org\/wiki\/Astrophysical_jet \"Astrophysical jet\") is inclined at an angle of 17° relative to the observer's line of sight and oriented on the plane of the sky at a [position angle](https:\/\/en.wikipedia.org\/wiki\/Position_angle \"Position angle\") of −72°.[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[34\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-34) From the enhanced brightness of the southern part of the ring due to [relativistic beaming](https:\/\/en.wikipedia.org\/wiki\/Relativistic_beaming \"Relativistic beaming\") of approaching funnel wall jet emission, EHT concluded the black hole, which anchors the jet, spins clockwise, as seen from Earth.[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[14\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-aasnova-20190410-14) EHT simulations allow for both prograde and retrograde inner disk rotation with respect to the black hole, while excluding zero black hole spin using a conservative minimum jet power of 1042 erg\/s via the [Blandford–Znajek process](https:\/\/en.wikipedia.org\/wiki\/Blandford%E2%80%93Znajek_process \"Blandford–Znajek process\").[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[35\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-35)\n\nProducing an image from data from an array of radio telescopes requires much mathematical work. Four independent teams created images to assess the reliability of the results.[\\[36\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-imaging-36) These methods included both an established algorithm in [radio astronomy](https:\/\/en.wikipedia.org\/wiki\/Radio_astronomy \"Radio astronomy\") for [image reconstruction](https:\/\/en.wikipedia.org\/wiki\/Image_reconstruction \"Image reconstruction\") known as [CLEAN](https:\/\/en.wikipedia.org\/wiki\/CLEAN_\\(algorithm\\) \"CLEAN (algorithm)\"), invented by [Jan Högbom](https:\/\/en.wikipedia.org\/wiki\/Jan_H%C3%B6gbom \"Jan Högbom\"),[\\[37\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-H%C3%B6gbom1974-37) as well as self-calibrating [image processing](https:\/\/en.wikipedia.org\/wiki\/Image_processing \"Image processing\") methods[\\[38\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-bnss,etc-38) for astronomy such as the [CHIRP algorithm](https:\/\/en.wikipedia.org\/wiki\/CHIRP_\\(algorithm\\) \"CHIRP (algorithm)\") created by [Katherine Bouman](https:\/\/en.wikipedia.org\/wiki\/Katherine_Bouman \"Katherine Bouman\") and others.[\\[36\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-imaging-36)[\\[39\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-39) The algorithms that were ultimately used were a [regularized](https:\/\/en.wikipedia.org\/wiki\/Regularization_\\(mathematics\\) \"Regularization (mathematics)\") [maximum likelihood](https:\/\/en.wikipedia.org\/wiki\/Maximum_likelihood \"Maximum likelihood\") (RML)[\\[40\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-40) algorithm and the [CLEAN](https:\/\/en.wikipedia.org\/wiki\/CLEAN_\\(algorithm\\) \"CLEAN (algorithm)\") algorithm.[\\[36\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-imaging-36)\n\nIn March 2020, astronomers proposed an improved way of seeing more of the rings in the first black hole image.[\\[41\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20200328-41)[\\[42\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-42) In March 2021, a new photo was revealed, showing how the M87 black hole looks in polarised light. This is the first time astronomers have been able to measure polarisation so close to the edge of a black hole. The lines on the photo mark the orientation of polarisation, which is related to the magnetic field around the shadow of the black hole.[\\[43\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-43)\n\nIn August 2022, a team led by [University of Waterloo](https:\/\/en.wikipedia.org\/wiki\/University_of_Waterloo \"University of Waterloo\") researcher Avery Broderick released a \"remaster\\[ed\\]\" version of original image generated from the data collected by the EHT. This image \"resolve\\[d\\] a fundamental signature of gravity around a black hole\", with it showing a displaying [photon ring](https:\/\/en.wikipedia.org\/wiki\/Photon_ring \"Photon ring\") around [M87\\*](https:\/\/en.wikipedia.org\/wiki\/M87* \"M87*\").[\\[44\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-44)[\\[45\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-45) The claim has been subsequently disputed.[\\[46\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-46)\n\nIn 2023, EHT released new, sharper images of the M87 black hole, reconstructed from the same 2017 data but created using the PRIMO algorithm.[\\[47\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-47)\n\n### 3C 279\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=4 \"Edit section: 3C 279\")\\]\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/d\/d7\/EHT3C279PressReleaseImage.png\/250px-EHT3C279PressReleaseImage.png)](https:\/\/en.wikipedia.org\/wiki\/File:EHT3C279PressReleaseImage.png)\n\nEHT image of the archetypal blazar 3C 279 showing a relativistic jet down to the AGN core surrounding the supermassive black hole.\n\nIn April 2020, the EHT released the first 20 microarcsecond resolution images of the archetypal [blazar](https:\/\/en.wikipedia.org\/wiki\/Blazar \"Blazar\") [3C 279](https:\/\/en.wikipedia.org\/wiki\/3C_279 \"3C 279\") it observed in April 2017.[\\[48\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-EHT3C279-48) These images, generated from observations over 4 nights in April 2017, reveal bright components of a jet whose projection on the observer plane exhibit apparent [superluminal motions](https:\/\/en.wikipedia.org\/wiki\/Superluminal_motion \"Superluminal motion\") with speeds up to 20 *c*.[\\[49\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-EHT3C279PressRelease-49) Such apparent superluminal motion from relativistic emitters such as an approaching jet is explained by emission originating closer to the observer (downstream along the jet) catching up with emission originating further from the observer (at the jet base) as the jet propagates close to the speed of light at small angles to the line of sight.\n\n### Centaurus A\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=5 \"Edit section: Centaurus A\")\\]\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/6\/61\/EHTcentaurusA2021.jpg\/250px-EHTcentaurusA2021.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:EHTcentaurusA2021.jpg)\n\nImage of Centaurus A showing its black hole jet at different scales\n\nIn July 2021, high resolution images of the jet produced by a supermassive black hole sitting at the center of [Centaurus A](https:\/\/en.wikipedia.org\/wiki\/Centaurus_A \"Centaurus A\") were released. With a mass around 5\\.5×107 [M☉](https:\/\/en.wikipedia.org\/wiki\/Solar_mass \"Solar mass\"), the black hole is not large enough for its [photon sphere](https:\/\/en.wikipedia.org\/wiki\/Photon_sphere \"Photon sphere\") to be observed, as in EHT images of Messier M87\\*, but its jet extends even beyond its host galaxy while staying as a highly collimated beam which is a point of study. Edge-brightening of the jet was also observed which would exclude models of particle acceleration that are unable to reproduce this effect. The image was 16 times sharper than previous observations and utilized a 1.3 mm wavelength.[\\[50\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-50)[\\[51\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-51)[\\[52\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-52)\n\n### Sagittarius A\\*\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=6 \"Edit section: Sagittarius A*\")\\]\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/9\/96\/EHT_Saggitarius_A_black_hole.tif\/lossy-page1-200px-EHT_Saggitarius_A_black_hole.tif.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:EHT_Saggitarius_A_black_hole.tif)\n\n[Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\"), first image released in 2022\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/3\/3e\/Sagittarius_Astar_in_polarised_light.tif\/lossy-page1-200px-Sagittarius_Astar_in_polarised_light.tif.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:Sagittarius_Astar_in_polarised_light.tif)\n\nSagittarius A\\* in polarised light, image released in 2024\n\nOn May 12, 2022, the EHT Collaboration revealed an image of [Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\"), the supermassive black hole at the [center](https:\/\/en.wikipedia.org\/wiki\/Galactic_Center \"Galactic Center\") of the [Milky Way](https:\/\/en.wikipedia.org\/wiki\/Milky_Way \"Milky Way\") [galaxy](https:\/\/en.wikipedia.org\/wiki\/Galaxy \"Galaxy\"). The black hole is 27,000 light-years away from Earth; it is thousands of times smaller than M87\\*. [Sera Markoff](https:\/\/en.wikipedia.org\/wiki\/Sera_Markoff \"Sera Markoff\"), Co-Chair of the EHT Science Council, said: \"We have two completely different types of galaxies and two very different black hole masses, but close to the edge of these black holes they look amazingly similar. This tells us that General Relativity governs these objects up close, and any differences we see further away must be due to differences in the material that surrounds the black holes.\"[\\[53\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-53)\n\nOn March 22, 2024, the EHT Collaboration released an image of Sagittarius A\\* in polarized light.[\\[54\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-54)\n\n### J1924-2914\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=7 \"Edit section: J1924-2914\")\\]\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/e\/e7\/EHTj1924-2914.png\/250px-EHTj1924-2914.png)](https:\/\/en.wikipedia.org\/wiki\/File:EHTj1924-2914.png)\n\nA multifrequency view of the bent jet in Blazar J1924-2914.[\\[55\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:1-55)[\\[56\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:2-56)\n\nIn August 2022, the EHT together with Global Millimeter VLBI Array and the [Very Long Baseline Array](https:\/\/en.wikipedia.org\/wiki\/Very_Long_Baseline_Array \"Very Long Baseline Array\") imaged the distant [blazar](https:\/\/en.wikipedia.org\/wiki\/Blazar \"Blazar\") J1924-2914. They operated at 230 GHz, 86 GHz and 2.3+8.7 GHz, respectively, the highest angular resolution images of polarized emission from a quasar ever obtained. Observations reveal a helically bent jet and the polarization of its emission suggest a toroidal magnetic field structure. The object is used as calibrator for Sagittarius A\\* sharing strong optical variability and polarization with it.[\\[55\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:1-55)[\\[56\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:2-56)\n\n### NRAO 530\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=8 \"Edit section: NRAO 530\")\\]\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/3\/3b\/NRAO_530_by_EHT_01.jpg\/250px-NRAO_530_by_EHT_01.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:NRAO_530_by_EHT_01.jpg)\n\nNRAO 530 by EHT. The total intensity is shown in grayscale with black contours indicating 10%, 25%, 50%, and 75% of the peak LP intensity. Black dotted contours indicate 25%, 50%, and 75% of the peak polarized intensity.\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/7\/77\/NRAO_530_by_EHT_02.jpg\/250px-NRAO_530_by_EHT_02.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:NRAO_530_by_EHT_02.jpg)\n\nSchematic of the total-intensity and LP components in the EHT fiducial image of NRAO 530; white contours show the total intensity levels; color scale and cyan contours represent the polarized intensity of the method-averaged image.\n\nIn February 2023, the EHT reported on the observations of the [quasar](https:\/\/en.wikipedia.org\/wiki\/Quasar \"Quasar\") NRAO 530. NRAO 530 (1730−130, J1733−1304) is a [flat-spectrum radio quasar](https:\/\/en.wikipedia.org\/wiki\/Flat-spectrum_radio_quasar \"Flat-spectrum radio quasar\") (FSRQ) that belongs to the class of bright γ-ray [blazars](https:\/\/en.wikipedia.org\/wiki\/Blazar \"Blazar\") and shows significant variability across the entire electromagnetic spectrum. The source was monitored by the University of Michigan Radio Observatory at 4.8, 8.4, and 14.5 GHz for several decades until 2012. The quasar underwent a dramatic radio outburst in 1997, during which its flux density at 14.5 GHz exceeded 10 Jy, while the average value is ~2 Jy. Since 2002, NRAO 530 has been monitored by the Submillimeter Array (SMA; Maunakea, Hawaii) at 1.3 mm and 870 μm. NRAO 530 has a redshift of *z* = 0.902 (Junkkarinen 1984), for which 100 μas corresponds to a linear distance of 6 billion pc. The source contains a supermassive black hole, the mass of which is currently uncertain, with estimates ranging from 3×108 *M*☉ to 2×109 *M*☉.[\\[57\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-nrao530-57)\n\nIt was observed with the Event Horizon Telescope on April 5−7, 2017, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A\\*. The observations were performed with the full EHT 2017 array of eight telescopes located at six geographical sites. At *z* = 0.902, this is the most distant object imaged by the EHT so far. The team reconstructed the first images of the source at 230 GHz, at an angular resolution of about 20 μas, both in total intensity and in linear polarization (LP). Source variability was not detected, that allowed to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which was associated with the core. The feature is linearly polarized, with a fractional polarization of about 5%–8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle about −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field.[\\[57\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-nrao530-57)\n\n## Collaborating institutes\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=9 \"Edit section: Collaborating institutes\")\\]\n\nThe EHT Collaboration consists of 13 stakeholder institutes:[\\[58\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-58)\n\n- the [Academia Sinica](https:\/\/en.wikipedia.org\/wiki\/Academia_Sinica \"Academia Sinica\") Institute of Astronomy and Astrophysics\n- the [University of Arizona](https:\/\/en.wikipedia.org\/wiki\/University_of_Arizona \"University of Arizona\")\n- the [University of Chicago](https:\/\/en.wikipedia.org\/wiki\/University_of_Chicago \"University of Chicago\")\n- the [East Asian Observatory](https:\/\/en.wikipedia.org\/w\/index.php?title=East_Asian_Observatory&action=edit&redlink=1 \"East Asian Observatory (page does not exist)\")\n- [Goethe University Frankfurt](https:\/\/en.wikipedia.org\/wiki\/Goethe_University_Frankfurt \"Goethe University Frankfurt\")\n- [Smithsonian Astrophysical Observatory](https:\/\/en.wikipedia.org\/wiki\/Smithsonian_Astrophysical_Observatory \"Smithsonian Astrophysical Observatory\") (part of the [Harvard–Smithsonian Center for Astrophysics](https:\/\/en.wikipedia.org\/wiki\/Harvard%E2%80%93Smithsonian_Center_for_Astrophysics \"Harvard–Smithsonian Center for Astrophysics\"))\n- [Institut de radioastronomie millimétrique](https:\/\/en.wikipedia.org\/wiki\/Institut_de_radioastronomie_millim%C3%A9trique \"Institut de radioastronomie millimétrique\") (IRAM, itself a collaboration between the French [CNRS](https:\/\/en.wikipedia.org\/wiki\/CNRS \"CNRS\"), the German [Max Planck Society](https:\/\/en.wikipedia.org\/wiki\/Max_Planck_Society \"Max Planck Society\"), and the Spanish [Instituto Geográfico Nacional](https:\/\/en.wikipedia.org\/wiki\/Instituto_Geogr%C3%A1fico_Nacional_\\(Spain\\) \"Instituto Geográfico Nacional (Spain)\"))\n- [Large Millimeter Telescope](https:\/\/en.wikipedia.org\/wiki\/Large_Millimeter_Telescope \"Large Millimeter Telescope\") Alfonso Serrano\n- [Max Planck Institute for Radio Astronomy](https:\/\/en.wikipedia.org\/wiki\/Max_Planck_Institute_for_Radio_Astronomy \"Max Planck Institute for Radio Astronomy\")\n- [MIT](https:\/\/en.wikipedia.org\/wiki\/MIT \"MIT\") [Haystack Observatory](https:\/\/en.wikipedia.org\/wiki\/Haystack_Observatory \"Haystack Observatory\")\n- [National Astronomical Observatory of Japan](https:\/\/en.wikipedia.org\/wiki\/National_Astronomical_Observatory_of_Japan \"National Astronomical Observatory of Japan\")\n- [Perimeter Institute for Theoretical Physics](https:\/\/en.wikipedia.org\/wiki\/Perimeter_Institute_for_Theoretical_Physics \"Perimeter Institute for Theoretical Physics\")\n- [Radboud University](https:\/\/en.wikipedia.org\/wiki\/Radboud_University \"Radboud University\")\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/1\/10\/Locations_of_the_telescopes_that_make_up_the_EHT_array_%28eso2208-eht-mwi%29.tiff\/lossy-page1-1000px-Locations_of_the_telescopes_that_make_up_the_EHT_array_%28eso2208-eht-mwi%29.tiff.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:Locations_of_the_telescopes_that_make_up_the_EHT_array_\\(eso2208-eht-mwi\\).tiff)\n\nLocations of the telescopes that make up the EHT array. A global map showing the radio observatories that form the Event Horizon Telescope (EHT) network used to image the Milky Way's central black hole, Sagittarius A\\*. The telescopes highlighted in yellow were part of the EHT network during the observations of Sagittarius A\\* in 2017. These include the Atacama Large Millimeter\/submillimeter Array (ALMA), the Atacama Pathfinder EXperiment (APEX), IRAM 30-meter telescope (30-M), James Clark Maxwell Telescope (JCMT), Large Millimeter Telescope (LMT), Submillimeter Array (SMA), Submillimetere Telescope (SMT) and South Pole Telescope (SPT). Highlighted in blue are the three telescopes added to the EHT Collaboration after 2018: the Greenland Telescope (GLT), the NOrthern Extended Millimeter Array (NOEMA) in France, and the University of Arizona ARO 12-meter Telescope at Kitt Peak.\n\n## Funding\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=10 \"Edit section: Funding\")\\]\n\nThe EHT Collaboration receives funding from numerous sources including:[\\[59\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-59)\n\n- [United States National Science Foundation](https:\/\/en.wikipedia.org\/wiki\/National_Science_Foundation \"National Science Foundation\")\n- [European Research Council](https:\/\/en.wikipedia.org\/wiki\/European_Research_Council \"European Research Council\")\n- [National Science and Technology Council of Taiwan](https:\/\/en.wikipedia.org\/wiki\/National_Science_and_Technology_Council_\\(Taiwan\\) \"National Science and Technology Council (Taiwan)\") (formerly Ministry of Science and Technology of Taiwan)\n- [Max Planck Society](https:\/\/en.wikipedia.org\/wiki\/Max_Planck_Society \"Max Planck Society\")\n- [Consejo Nacional de Ciencia y Technologia, Mexico](https:\/\/en.wikipedia.org\/wiki\/Consejo_Nacional_de_Ciencia_y_Tecnolog%C3%ADa_\\(Mexico\\) \"Consejo Nacional de Ciencia y Tecnología (Mexico)\")\n- [John Templeton Foundation](https:\/\/en.wikipedia.org\/wiki\/John_Templeton_Foundation \"John Templeton Foundation\")\n- [Gordon and Betty Moore Foundation](https:\/\/en.wikipedia.org\/wiki\/Gordon_and_Betty_Moore_Foundation \"Gordon and Betty Moore Foundation\")\n- [Japan Society for the Promotion of Science](https:\/\/en.wikipedia.org\/wiki\/Japan_Society_for_the_Promotion_of_Science \"Japan Society for the Promotion of Science\")\n- [Natural Sciences and Engineering Research Council of Canada](https:\/\/en.wikipedia.org\/wiki\/Natural_Sciences_and_Engineering_Research_Council \"Natural Sciences and Engineering Research Council\")\n- [Academia Sinica](https:\/\/en.wikipedia.org\/wiki\/Academia_Sinica \"Academia Sinica\")\n- [Smithsonian Institution](https:\/\/en.wikipedia.org\/wiki\/Smithsonian_Institution \"Smithsonian Institution\")\n\nAdditionally, [Western Digital](https:\/\/en.wikipedia.org\/wiki\/Western_Digital \"Western Digital\") and [Xilinx](https:\/\/en.wikipedia.org\/wiki\/Xilinx \"Xilinx\") are industry donors.[\\[60\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-60)\n\n## References\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=11 \"Edit section: References\")\\]\n\n1. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-eht-wp-2009_1-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-eht-wp-2009_1-1)\n   Doeleman, Sheperd (June 21, 2009). \"Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole\". *Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers*. **2010**: 68. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[0906\\.3899](https:\/\/arxiv.org\/abs\/0906.3899). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2009astro2010S..68D](https:\/\/ui.adsabs.harvard.edu\/abs\/2009astro2010S..68D).\n2. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-1) [***c***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-2) [***d***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-3) [***e***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-4) [***f***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-5)\n   The Event Horizon Telescope Collaboration (April 10, 2019). [\"First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole\"](https:\/\/doi.org\/10.3847%2F2041-8213%2Fab0ec7). *[The Astrophysical Journal Letters](https:\/\/en.wikipedia.org\/wiki\/The_Astrophysical_Journal_Letters \"The Astrophysical Journal Letters\")*. **875** (1): L1. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[1906\\.11238](https:\/\/arxiv.org\/abs\/1906.11238). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2019ApJ...875L...1E](https:\/\/ui.adsabs.harvard.edu\/abs\/2019ApJ...875L...1E). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.3847\/2041-8213\/ab0ec7](https:\/\/doi.org\/10.3847%2F2041-8213%2Fab0ec7). 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[\"The creation of the algorithm that made the first black hole image possible was led by MIT grad student Katie Bouman\"](https:\/\/techcrunch.com\/2019\/04\/10\/the-creation-of-the-algorithm-that-made-the-first-black-hole-image-possible-was-led-by-mit-grad-student-katie-bouman\/). *TechCrunch*. Retrieved April 15, 2019.\n40. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-40)**\n    Narayan, Ramesh; Nityananda, Rajaram (1986). \"Maximum Entropy Image Restoration in Astronomy\". *Annual Review of Astronomy and Astrophysics*. **24**: 127–170\\. [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[1986ARA\\&A..24..127N](https:\/\/ui.adsabs.harvard.edu\/abs\/1986ARA&A..24..127N). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1146\/annurev.aa.24.090186.001015](https:\/\/doi.org\/10.1146%2Fannurev.aa.24.090186.001015).\n41. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-NYT-20200328_41-0)**\n    [Overbye, Dennis](https:\/\/en.wikipedia.org\/wiki\/Dennis_Overbye \"Dennis Overbye\") (March 28, 2020). [\"Infinite Visions Were Hiding in the First Black Hole Image's Rings\"](https:\/\/www.nytimes.com\/2020\/03\/28\/science\/black-hole-rings.html). *[The New York Times](https:\/\/en.wikipedia.org\/wiki\/The_New_York_Times \"The New York Times\")*. Retrieved March 29, 2020.\n42. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-42)**\n    Johnson, Michael D.; et al. (March 18, 2020). [\"Universal interferometric signatures of a black hole's photon ring\"](https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7080443). *[Science Advances](https:\/\/en.wikipedia.org\/wiki\/Science_Advances \"Science Advances\")*. **6** (12, eaaz1310) eaaz1310. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[1907\\.04329](https:\/\/arxiv.org\/abs\/1907.04329). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2020SciA....6.1310J](https:\/\/ui.adsabs.harvard.edu\/abs\/2020SciA....6.1310J). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1126\/sciadv.aaz1310](https:\/\/doi.org\/10.1126%2Fsciadv.aaz1310). [PMC](https:\/\/en.wikipedia.org\/wiki\/PMC_\\(identifier\\) \"PMC (identifier)\") [7080443](https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7080443). [PMID](https:\/\/en.wikipedia.org\/wiki\/PMID_\\(identifier\\) \"PMID (identifier)\") [32206723](https:\/\/pubmed.ncbi.nlm.nih.gov\/32206723).\n43. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-43)**\n    [\"A view of the M87 supermassive black hole in polarised light\"](https:\/\/www.eso.org\/public\/images\/eso2105a\/). ESO. Retrieved March 24, 2021.\n44. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-44)**\n    [\"The photon ring: a black hole ready for its close-up\"](https:\/\/uwaterloo.ca\/news\/media\/photon-ring-black-hole-ready-its-close). *Waterloo News*. August 16, 2022. Retrieved August 28, 2022.\n45. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-45)**\n    Lea, Robert (August 17, 2022). [\"Supermassive black hole's bright 'photon ring' revealed in new image\"](https:\/\/www.space.com\/supermassive-black-hole-photon-ring-image). *Space.com*. Retrieved August 28, 2022.\n46. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-46)**\n    [\"Physicists dispute a claim of detecting a black hole's 'photon ring'\"](https:\/\/www.sciencenews.org\/article\/disputed-photon-ring-supermassive-black-hole-image-eht). *Science News*. August 31, 2022. Retrieved September 19, 2022.\n47. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-47)**\n    Medeiros, Lia; Psaltis, Dimitrios; Lauer, Tod R.; Özel, Feryal (April 1, 2023). [\"The Image of the M87 Black Hole Reconstructed with PRIMO\"](https:\/\/doi.org\/10.3847%2F2041-8213%2Facc32d). *The Astrophysical Journal Letters*. **947** (1): L7. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[2304\\.06079](https:\/\/arxiv.org\/abs\/2304.06079). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2023ApJ...947L...7M](https:\/\/ui.adsabs.harvard.edu\/abs\/2023ApJ...947L...7M). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.3847\/2041-8213\/acc32d](https:\/\/doi.org\/10.3847%2F2041-8213%2Facc32d). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [258108405](https:\/\/api.semanticscholar.org\/CorpusID:258108405).\n48. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-EHT3C279_48-0)**\n    Kim, Jae-Young; et al. (April 5, 2020). [\"Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution\"](https:\/\/doi.org\/10.1051%2F0004-6361%2F202037493). *Astronomy & Astrophysics*. **640**: A69. [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2020A\\&A...640A..69K](https:\/\/ui.adsabs.harvard.edu\/abs\/2020A&A...640A..69K). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1051\/0004-6361\/202037493](https:\/\/doi.org\/10.1051%2F0004-6361%2F202037493). [hdl](https:\/\/en.wikipedia.org\/wiki\/Hdl_\\(identifier\\) \"Hdl (identifier)\"):[10261\/227201](https:\/\/hdl.handle.net\/10261%2F227201).\n49. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-EHT3C279PressRelease_49-0)**\n    [\"Something is Lurking in the Heart of Quasar 3C 279\"](https:\/\/eventhorizontelescope.org\/blog\/something-is-lurking-in-the-heart-of-quasar-3c-279). *Event Horizon Telescope*. Retrieved April 20, 2019.\n50. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-50)**\n    Janssen, Michael; Falcke, Heino; Kadler, Matthias; Ros, Eduardo; Wielgus, Maciek; Akiyama, Kazunori; et al. (July 19, 2021). [\"Event Horizon Telescope observations of the jet launching and collimation in Centaurus A\"](https:\/\/doi.org\/10.1038%2Fs41550-021-01417-w). *Nature Astronomy*. **5** (10): 1017–1028\\. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[2111\\.03356](https:\/\/arxiv.org\/abs\/2111.03356). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2021NatAs...5.1017J](https:\/\/ui.adsabs.harvard.edu\/abs\/2021NatAs...5.1017J). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1038\/s41550-021-01417-w](https:\/\/doi.org\/10.1038%2Fs41550-021-01417-w). [ISSN](https:\/\/en.wikipedia.org\/wiki\/ISSN_\\(identifier\\) \"ISSN (identifier)\") [2397-3366](https:\/\/search.worldcat.org\/issn\/2397-3366).\n51. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-51)**\n    Gabuzda, Denise C. (July 19, 2021). \"Peering into the heart of an active galaxy\". *Nature Astronomy*. **5** (10): 982–983\\. [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2021NatAs...5..982G](https:\/\/ui.adsabs.harvard.edu\/abs\/2021NatAs...5..982G). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1038\/s41550-021-01420-1](https:\/\/doi.org\/10.1038%2Fs41550-021-01420-1). [ISSN](https:\/\/en.wikipedia.org\/wiki\/ISSN_\\(identifier\\) \"ISSN (identifier)\") [2397-3366](https:\/\/search.worldcat.org\/issn\/2397-3366). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [237675257](https:\/\/api.semanticscholar.org\/CorpusID:237675257).\n52. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-52)**\n    [\"EHT Pinpoints Dark Heart of the Nearest Radio Galaxy\"](https:\/\/eventhorizontelescope.org\/blog\/eht-pinpoints-dark-heart-nearest-radio-galaxy). Event Horizon Telescope. July 19, 2021. Retrieved July 20, 2021.\n53. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-53)**\n    [\"Astronomers reveal first image of the black hole at the heart of our galaxy\"](https:\/\/www.eso.org\/public\/news\/eso2208-eht-mw\/) (Press release). ESO. May 12, 2022.\n54. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-54)**\n    [\"Astronomers unveil strong magnetic fields spiraling at the edge of Milky Way's central black hole\"](https:\/\/www.eso.org\/public\/news\/eso2406\/). *ESO*. Retrieved March 27, 2024.\n55. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:1_55-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:1_55-1)\n    Issaoun, Sara; Wielgus, Maciek; Jorstad, Svetlana; Krichbaum, Thomas P.; Blackburn, Lindy; Janssen, Michael; Chan, Chi-kwan; Pesce, Dominic W.; Gómez, José L.; Akiyama, Kazunori; Mościbrodzka, Monika; Martí-Vidal, Iván; Chael, Andrew; Lico, Rocco; Liu, Jun (August 1, 2022). [\"Resolving the Inner Parsec of the Blazar J1924–2914 with the Event Horizon Telescope\"](https:\/\/doi.org\/10.3847%2F1538-4357%2Fac7a40). *The Astrophysical Journal*. **934** (2): 145. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[2208\\.01662](https:\/\/arxiv.org\/abs\/2208.01662). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2022ApJ...934..145I](https:\/\/ui.adsabs.harvard.edu\/abs\/2022ApJ...934..145I). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.3847\/1538-4357\/ac7a40](https:\/\/doi.org\/10.3847%2F1538-4357%2Fac7a40). [ISSN](https:\/\/en.wikipedia.org\/wiki\/ISSN_\\(identifier\\) \"ISSN (identifier)\") [0004-637X](https:\/\/search.worldcat.org\/issn\/0004-637X). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [251274752](https:\/\/api.semanticscholar.org\/CorpusID:251274752).\n56. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:2_56-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:2_56-1)\n    [\"Resolving the core of the J1924-2914 blazar with the Event Horizon Telescope\"](https:\/\/eventhorizontelescope.org\/blog\/resolving-core-j1924-2914-blazar-event-horizon-telescope). *Event Horizon Telescope*. August 6, 2022. Retrieved August 14, 2022.\n57. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-nrao530_57-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-nrao530_57-1)\n    Jorstad, Svetlana; et al. (February 1, 2023). [\"The Event Horizon Telescope Image of the Quasar NRAO 530\"](https:\/\/doi.org\/10.3847%2F1538-4357%2Facaea8). *The Astrophysical Journal*. **943** (2): 170. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[2302\\.04622](https:\/\/arxiv.org\/abs\/2302.04622). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2023ApJ...943..170J](https:\/\/ui.adsabs.harvard.edu\/abs\/2023ApJ...943..170J). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.3847\/1538-4357\/acaea8](https:\/\/doi.org\/10.3847%2F1538-4357%2Facaea8). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [256661718](https:\/\/api.semanticscholar.org\/CorpusID:256661718).\n    \n    [![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/e\/e1\/CC_BY_icon.svg\/60px-CC_BY_icon.svg.png)](https:\/\/en.wikipedia.org\/wiki\/File:CC_BY_icon.svg) Material was copied from this source, which is available under a [Creative Commons Attribution 4.0](https:\/\/creativecommons.org\/licenses\/by\/3.0\/).\n58. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-58)** [Event Horizon Telescopoe, Organisation](http:\/\/eventhorizontelescope.org\/organization), EHT Website, accessed: 2022-01-30.\n59. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-59)**\n    [\"Funding Support\"](https:\/\/eventhorizontelescope.org\/funding-support). *eventhorizontelescope.org*. Retrieved September 27, 2023.\n60. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-60)**\n    [\"Industry Donors\"](https:\/\/eventhorizontelescope.org\/industry-donors). *eventhorizontelescope.org*. Retrieved September 27, 2023.\n\n## External links\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=12 \"Edit section: External links\")\\]\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/4\/4a\/Commons-logo.svg\/40px-Commons-logo.svg.png)](https:\/\/en.wikipedia.org\/wiki\/File:Commons-logo.svg)\n\nWikimedia Commons has media related to [Event Horizon Telescope](https:\/\/commons.wikimedia.org\/wiki\/Category:Event_Horizon_Telescope \"commons:Category:Event Horizon Telescope\").\n\n- [Official website](https:\/\/eventhorizontelescope.org\/) [![Edit this at Wikidata](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/8\/8a\/OOjs_UI_icon_edit-ltr-progressive.svg\/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https:\/\/www.wikidata.org\/wiki\/Q3944788#P856 \"Edit this at Wikidata\")\n- [EHT \"Ask Me Anything\" (AMA) serie](https:\/\/www.reddit.com\/r\/askscience\/comments\/olel36\/askscience_ama_series_were_event_horizon_horizon\/) on [reddit](https:\/\/en.wikipedia.org\/wiki\/Reddit \"Reddit\")\n- [The Next Generation Event Horizon Telescope](https:\/\/www.ngeht.org\/)\n\n| [v](https:\/\/en.wikipedia.org\/wiki\/Template:Radio_astronomy \"Template:Radio astronomy\") [t](https:\/\/en.wikipedia.org\/wiki\/Template_talk:Radio_astronomy \"Template talk:Radio astronomy\") [e](https:\/\/en.wikipedia.org\/wiki\/Special:EditPage\/Template:Radio_astronomy \"Special:EditPage\/Template:Radio astronomy\")[Radio astronomy](https:\/\/en.wikipedia.org\/wiki\/Radio_astronomy \"Radio astronomy\") |   |\n|---|---|\n| Concepts | Units ([watt](https:\/\/en.wikipedia.org\/wiki\/Watt \"Watt\") and [jansky](https:\/\/en.wikipedia.org\/wiki\/Jansky \"Jansky\")) [Radio telescope](https:\/\/en.wikipedia.org\/wiki\/Radio_telescope \"Radio telescope\") ([Radio window](https:\/\/en.wikipedia.org\/wiki\/Radio_window \"Radio window\")) [Astronomical interferometer](https:\/\/en.wikipedia.org\/wiki\/Astronomical_interferometer \"Astronomical interferometer\") ([History](https:\/\/en.wikipedia.org\/wiki\/Astronomical_interferometer#History \"Astronomical interferometer\")) [Very Long Baseline Interferometry](https:\/\/en.wikipedia.org\/wiki\/Very-long-baseline_interferometry \"Very-long-baseline interferometry\") (VLBI) [Astronomical radio source](https:\/\/en.wikipedia.org\/wiki\/Astronomical_radio_source \"Astronomical radio source\") |\n| [Radio telescopes](https:\/\/en.wikipedia.org\/wiki\/Category:Radio_telescopes \"Category:Radio telescopes\") ([List](https:\/\/en.wikipedia.org\/wiki\/List_of_radio_telescopes \"List of radio telescopes\")) |   |\n|   |   |\n| Individual telescopes | [500 meter Aperture Spherical Telescope](https:\/\/en.wikipedia.org\/wiki\/Five-hundred-meter_Aperture_Spherical_Telescope \"Five-hundred-meter Aperture Spherical Telescope\") (FAST, China) [Arecibo Telescope](https:\/\/en.wikipedia.org\/wiki\/Arecibo_Telescope \"Arecibo Telescope\") (Puerto Rico, US) [Caltech Submillimeter Observatory](https:\/\/en.wikipedia.org\/wiki\/Caltech_Submillimeter_Observatory \"Caltech Submillimeter Observatory\") (CSO, US) [Effelsberg Telescope](https:\/\/en.wikipedia.org\/wiki\/Effelsberg_100-m_Radio_Telescope \"Effelsberg 100-m Radio Telescope\") (Germany) [Galenki RT-70](https:\/\/en.wikipedia.org\/wiki\/Galenki_RT-70_radio_telescope \"Galenki RT-70 radio telescope\") (Russia) [Green Bank Telescope](https:\/\/en.wikipedia.org\/wiki\/Green_Bank_Telescope \"Green Bank Telescope\") (West Virginia, US) [Large Millimeter Telescope](https:\/\/en.wikipedia.org\/wiki\/Large_Millimeter_Telescope \"Large Millimeter Telescope\") (Mexico) [Lovell Telescope](https:\/\/en.wikipedia.org\/wiki\/Lovell_Telescope \"Lovell Telescope\") (UK) [Ooty Telescope](https:\/\/en.wikipedia.org\/wiki\/Ooty_Radio_Telescope \"Ooty Radio Telescope\") (India) [Qitai Radio Telescope](https:\/\/en.wikipedia.org\/wiki\/Qitai_Radio_Telescope \"Qitai Radio Telescope\") (China) [RATAN-600 Radio Telescope](https:\/\/en.wikipedia.org\/wiki\/RATAN-600 \"RATAN-600\") (Russia) [Sardinia Radio Telescope](https:\/\/en.wikipedia.org\/wiki\/Sardinia_Radio_Telescope \"Sardinia Radio Telescope\") (Italy) [Suffa RT-70](https:\/\/en.wikipedia.org\/wiki\/Suffa_RT-70_radio_telescope \"Suffa RT-70 radio telescope\") (Uzbekistan) [Usuda Telescope](https:\/\/en.wikipedia.org\/wiki\/Usuda_Deep_Space_Center \"Usuda Deep Space Center\") (Japan) [UTR-2 decameter radio telescope](https:\/\/en.wikipedia.org\/wiki\/Ukrainian_T-shaped_Radio_telescope,_second_modification \"Ukrainian T-shaped Radio telescope, second modification\") (Ukraine) [Yevpatoria RT-70](https:\/\/en.wikipedia.org\/wiki\/Yevpatoria_RT-70_radio_telescope \"Yevpatoria RT-70 radio telescope\") (Ukraine) Southern Hemisphere [HartRAO](https:\/\/en.wikipedia.org\/wiki\/Hartebeesthoek_Radio_Astronomy_Observatory \"Hartebeesthoek Radio Astronomy Observatory\") (South Africa) [Parkes Observatory](https:\/\/en.wikipedia.org\/wiki\/Parkes_Observatory \"Parkes Observatory\") (Australia) [Warkworth Radio Astronomical Observatory](https:\/\/en.wikipedia.org\/wiki\/Warkworth_Radio_Astronomical_Observatory \"Warkworth Radio Astronomical Observatory\") (NZ) |\n| Interferometers | [Allen Telescope Array](https:\/\/en.wikipedia.org\/wiki\/Allen_Telescope_Array \"Allen Telescope Array\") (ATA, California, US) [Atacama Large Millimeter Array](https:\/\/en.wikipedia.org\/wiki\/Atacama_Large_Millimeter_Array \"Atacama Large Millimeter Array\") (ALMA, Chile) [Australia Telescope Compact Array](https:\/\/en.wikipedia.org\/wiki\/Australia_Telescope_Compact_Array \"Australia Telescope Compact Array\") (ATCA, Australia) [Australian Square Kilometre Array Pathfinder](https:\/\/en.wikipedia.org\/wiki\/Australian_Square_Kilometre_Array_Pathfinder \"Australian Square Kilometre Array Pathfinder\") (ASKAP, Australia) [Canadian Hydrogen Intensity Mapping Experiment](https:\/\/en.wikipedia.org\/wiki\/Canadian_Hydrogen_Intensity_Mapping_Experiment \"Canadian Hydrogen Intensity Mapping Experiment\") (CHIME, Canada) [Combined Array for Research in Millimeter-wave Astronomy](https:\/\/en.wikipedia.org\/wiki\/Combined_Array_for_Research_in_Millimeter-wave_Astronomy \"Combined Array for Research in Millimeter-wave Astronomy\") (CARMA, California, US) [European VLBI Network](https:\/\/en.wikipedia.org\/wiki\/European_VLBI_Network \"European VLBI Network\") (Europe) [Event Horizon Telescope]() (EHT) [Giant Metrewave Radio Telescope](https:\/\/en.wikipedia.org\/wiki\/Giant_Metrewave_Radio_Telescope \"Giant Metrewave Radio Telescope\") (GMRT, India) [Green Bank Interferometer](https:\/\/en.wikipedia.org\/wiki\/Green_Bank_Interferometer \"Green Bank Interferometer\") (GBI, West Virginia, US) [Korean VLBI Network](https:\/\/en.wikipedia.org\/wiki\/Korean_VLBI_Network \"Korean VLBI Network\") (KVN, South Korea) [Large Latin American Millimeter Array](https:\/\/en.wikipedia.org\/wiki\/Large_Latin_American_Millimeter_Array \"Large Latin American Millimeter Array\") (LLAMA, Argentina\/Brazil) [Long Wavelength Array](https:\/\/en.wikipedia.org\/wiki\/Long_Wavelength_Array \"Long Wavelength Array\") (LWA, New Mexico, US) [Low-Frequency Array](https:\/\/en.wikipedia.org\/wiki\/Low-Frequency_Array_\\(LOFAR\\) \"Low-Frequency Array (LOFAR)\") (LOFAR, Netherlands) [MeerKAT](https:\/\/en.wikipedia.org\/wiki\/MeerKAT \"MeerKAT\") (South Africa) [Molonglo Observatory Synthesis Telescope](https:\/\/en.wikipedia.org\/wiki\/Molonglo_Observatory_Synthesis_Telescope \"Molonglo Observatory Synthesis Telescope\") (MOST, Australia) [Multi-Element Radio Linked Interferometer Network](https:\/\/en.wikipedia.org\/wiki\/MERLIN \"MERLIN\") (MERLIN, UK) [Murchison Widefield Array](https:\/\/en.wikipedia.org\/wiki\/Murchison_Widefield_Array \"Murchison Widefield Array\") (MWA, Australia) [Northern Cross Radio Telescope](https:\/\/en.wikipedia.org\/wiki\/Northern_Cross_Radio_Telescope \"Northern Cross Radio Telescope\") (Italy) [Northern Extended Millimeter Array](https:\/\/en.wikipedia.org\/wiki\/Northern_Extended_Millimeter_Array \"Northern Extended Millimeter Array\") (France) [One-Mile Telescope](https:\/\/en.wikipedia.org\/wiki\/One-Mile_Telescope \"One-Mile Telescope\") (UK) [Primeval Structure Telescope](https:\/\/en.wikipedia.org\/wiki\/Primeval_Structure_Telescope \"Primeval Structure Telescope\") (PaST, China) [Square Kilometre Array](https:\/\/en.wikipedia.org\/wiki\/Square_Kilometre_Array \"Square Kilometre Array\") (SKA, Australia, South Africa) [Submillimeter Array](https:\/\/en.wikipedia.org\/wiki\/Submillimeter_Array \"Submillimeter Array\") (SMA, US) [Very Large Array](https:\/\/en.wikipedia.org\/wiki\/Very_Large_Array \"Very Large Array\") (VLA, New Mexico, US) [Very Long Baseline Array](https:\/\/en.wikipedia.org\/wiki\/Very_Long_Baseline_Array \"Very Long Baseline Array\") (VLBA, US) [Westerbork Synthesis Radio Telescope](https:\/\/en.wikipedia.org\/wiki\/Westerbork_Synthesis_Radio_Telescope \"Westerbork Synthesis Radio Telescope\") (WSRT, Netherlands) |\n| Space-based | [HALCA](https:\/\/en.wikipedia.org\/wiki\/HALCA \"HALCA\") (Japan) [Spektr-R](https:\/\/en.wikipedia.org\/wiki\/Spektr-R \"Spektr-R\") (Russia) |\n| [Observatories](https:\/\/en.wikipedia.org\/wiki\/Category:Radio_observatories \"Category:Radio observatories\") | [Algonquin Radio Observatory](https:\/\/en.wikipedia.org\/wiki\/Algonquin_Radio_Observatory \"Algonquin Radio Observatory\") (Canada) [Arecibo Observatory](https:\/\/en.wikipedia.org\/wiki\/Arecibo_Observatory \"Arecibo Observatory\") (Puerto Rico, US) [Green Bank Observatory](https:\/\/en.wikipedia.org\/wiki\/Green_Bank_Observatory \"Green Bank Observatory\") (US) [Haystack Observatory](https:\/\/en.wikipedia.org\/wiki\/Haystack_Observatory \"Haystack Observatory\") (US) [Jodrell Bank Observatory](https:\/\/en.wikipedia.org\/wiki\/Jodrell_Bank_Observatory \"Jodrell Bank Observatory\") (UK) [Mullard Radio Astronomy Observatory](https:\/\/en.wikipedia.org\/wiki\/Mullard_Radio_Astronomy_Observatory \"Mullard Radio Astronomy Observatory\") (UK) [National Radio Astronomy Observatory](https:\/\/en.wikipedia.org\/wiki\/National_Radio_Astronomy_Observatory \"National Radio Astronomy Observatory\") (US) [Nançay Radio Observatory](https:\/\/en.wikipedia.org\/wiki\/Nan%C3%A7ay_Radio_Observatory \"Nançay Radio Observatory\") (France) [Onsala Space Observatory](https:\/\/en.wikipedia.org\/wiki\/Onsala_Space_Observatory \"Onsala Space Observatory\") (Sweden) [Pushchino Radio Astronomy Observatory](https:\/\/en.wikipedia.org\/wiki\/Pushchino_Radio_Astronomy_Observatory \"Pushchino Radio Astronomy Observatory\") (PRAO ASC LPI, Russia) [Special Astrophysical Observatory of the Russian Academy of Science](https:\/\/en.wikipedia.org\/wiki\/Special_Astrophysical_Observatory_of_the_Russian_Academy_of_Science \"Special Astrophysical Observatory of the Russian Academy of Science\") (SAORAS, Russia) [Vermilion River Observatory](https:\/\/en.wikipedia.org\/wiki\/Vermilion_River_Observatory \"Vermilion River Observatory\") (US) |\n| Multi-use | [DRAO](https:\/\/en.wikipedia.org\/wiki\/Dominion_Radio_Astrophysical_Observatory \"Dominion Radio Astrophysical Observatory\") (Canada) [ESA New Norcia](https:\/\/en.wikipedia.org\/wiki\/New_Norcia_Station \"New Norcia Station\") (Australia) [PARL](https:\/\/en.wikipedia.org\/wiki\/Prince_Albert_Radar_Laboratory \"Prince Albert Radar Laboratory\") (Canada) |\n| People | [Elizabeth Alexander](https:\/\/en.wikipedia.org\/wiki\/Elizabeth_Alexander_\\(scientist\\) \"Elizabeth Alexander (scientist)\") [John G. Bolton](https:\/\/en.wikipedia.org\/wiki\/John_Gatenby_Bolton \"John Gatenby Bolton\") [Edward George Bowen](https:\/\/en.wikipedia.org\/wiki\/Edward_George_Bowen \"Edward George Bowen\") [Ronald Bracewell](https:\/\/en.wikipedia.org\/wiki\/Ronald_N._Bracewell \"Ronald N. Bracewell\") [Jocelyn Bell Burnell](https:\/\/en.wikipedia.org\/wiki\/Jocelyn_Bell_Burnell \"Jocelyn Bell Burnell\") [Arthur Covington](https:\/\/en.wikipedia.org\/wiki\/Arthur_Covington \"Arthur Covington\") [Nan Dieter-Conklin](https:\/\/en.wikipedia.org\/wiki\/Nan_Dieter-Conklin \"Nan Dieter-Conklin\") [Frank Drake](https:\/\/en.wikipedia.org\/wiki\/Frank_Drake \"Frank Drake\") [Cyril Hazard](https:\/\/en.wikipedia.org\/wiki\/Cyril_Hazard \"Cyril Hazard\") [Antony Hewish](https:\/\/en.wikipedia.org\/wiki\/Antony_Hewish \"Antony Hewish\") [Sebastian von Hoerner](https:\/\/en.wikipedia.org\/wiki\/Sebastian_von_Hoerner \"Sebastian von Hoerner\") [Karl Guthe Jansky](https:\/\/en.wikipedia.org\/wiki\/Karl_Guthe_Jansky \"Karl Guthe Jansky\") [Kenneth Kellermann](https:\/\/en.wikipedia.org\/wiki\/Kenneth_Kellermann \"Kenneth Kellermann\") [Frank J. Kerr](https:\/\/en.wikipedia.org\/wiki\/Frank_John_Kerr \"Frank John Kerr\") [John D. Kraus](https:\/\/en.wikipedia.org\/wiki\/John_D._Kraus \"John D. Kraus\") [Bernard Lovell](https:\/\/en.wikipedia.org\/wiki\/Bernard_Lovell \"Bernard Lovell\") [Christiaan Alexander Muller](https:\/\/en.wikipedia.org\/wiki\/Christiaan_Alexander_Muller \"Christiaan Alexander Muller\") [Jan Oort](https:\/\/en.wikipedia.org\/wiki\/Jan_Oort \"Jan Oort\") [Joseph Lade Pawsey](https:\/\/en.wikipedia.org\/wiki\/Joseph_L._Pawsey \"Joseph L. Pawsey\") [Ruby Payne-Scott](https:\/\/en.wikipedia.org\/wiki\/Ruby_Payne-Scott \"Ruby Payne-Scott\") [Arno Penzias](https:\/\/en.wikipedia.org\/wiki\/Arno_Allan_Penzias \"Arno Allan Penzias\") [Grote Reber](https:\/\/en.wikipedia.org\/wiki\/Grote_Reber \"Grote Reber\") [Martin Ryle](https:\/\/en.wikipedia.org\/wiki\/Martin_Ryle \"Martin Ryle\") [Govind Swarup](https:\/\/en.wikipedia.org\/wiki\/Govind_Swarup \"Govind Swarup\") [Gart Westerhout](https:\/\/en.wikipedia.org\/wiki\/Gart_Westerhout \"Gart Westerhout\") [Paul Wild](https:\/\/en.wikipedia.org\/wiki\/Paul_Wild_\\(Australian_scientist\\) \"Paul Wild (Australian scientist)\") [Robert Wilson](https:\/\/en.wikipedia.org\/wiki\/Robert_Woodrow_Wilson \"Robert Woodrow Wilson\") |\n| Astronomy by  EM methods | [Submillimetre astronomy](https:\/\/en.wikipedia.org\/wiki\/Submillimetre_astronomy \"Submillimetre astronomy\") [Infrared astronomy](https:\/\/en.wikipedia.org\/wiki\/Infrared_astronomy \"Infrared astronomy\") [Optical astronomy](https:\/\/en.wikipedia.org\/wiki\/Visible-light_astronomy \"Visible-light astronomy\") [High-energy astronomy](https:\/\/en.wikipedia.org\/wiki\/High-energy_astronomy \"High-energy astronomy\") [Gravitational-wave astronomy](https:\/\/en.wikipedia.org\/wiki\/Gravitational-wave_astronomy \"Gravitational-wave astronomy\") |\n| Related articles | [Aperture synthesis](https:\/\/en.wikipedia.org\/wiki\/Aperture_synthesis \"Aperture synthesis\") [Cosmic microwave background radiation](https:\/\/en.wikipedia.org\/wiki\/Cosmic_microwave_background \"Cosmic microwave background\") [Interferometry](https:\/\/en.wikipedia.org\/wiki\/Interferometry \"Interferometry\") [Odd radio circle](https:\/\/en.wikipedia.org\/wiki\/Odd_radio_circle \"Odd radio circle\") [Pulsar timing array](https:\/\/en.wikipedia.org\/wiki\/Pulsar_timing_array \"Pulsar timing array\") [Radio propagation](https:\/\/en.wikipedia.org\/wiki\/Radio_propagation \"Radio propagation\") [SETI](https:\/\/en.wikipedia.org\/wiki\/Search_for_extraterrestrial_intelligence \"Search for extraterrestrial intelligence\") [Wow! signal](https:\/\/en.wikipedia.org\/wiki\/Wow!_signal \"Wow! signal\") [HD 164595 signal](https:\/\/en.wikipedia.org\/wiki\/HD_164595 \"HD 164595\") [Solar radio emission](https:\/\/en.wikipedia.org\/wiki\/Solar_radio_emission \"Solar radio emission\") |\n| ![](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/9\/96\/Symbol_category_class.svg\/20px-Symbol_category_class.svg.png) [Category](https:\/\/en.wikipedia.org\/wiki\/Category:Radio_astronomy \"Category:Radio astronomy\") [![](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/4\/4a\/Commons-logo.svg\/20px-Commons-logo.svg.png)](https:\/\/en.wikipedia.org\/wiki\/File:Commons-logo.svg \"Commons page\") [Commons](https:\/\/commons.wikimedia.org\/wiki\/Category:Radio_astronomy \"commons:Category:Radio astronomy\") |   |\n\n[Portals](https:\/\/en.wikipedia.org\/wiki\/Wikipedia:Contents\/Portals \"Wikipedia:Contents\/Portals\"):\n\n- ![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/0\/00\/Crab_Nebula.jpg\/20px-Crab_Nebula.jpg) [Astronomy](https:\/\/en.wikipedia.org\/wiki\/Portal:Astronomy \"Portal:Astronomy\")\n- [![icon](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/5\/5f\/He1523a.jpg\/20px-He1523a.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:He1523a.jpg) [Stars](https:\/\/en.wikipedia.org\/wiki\/Portal:Stars \"Portal:Stars\")\n- ![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/5\/5c\/Earth-moon.jpg\/40px-Earth-moon.jpg) [Outer space](https:\/\/en.wikipedia.org\/wiki\/Portal:Outer_space \"Portal:Outer space\")\n\n![](https:\/\/en.wikipedia.org\/wiki\/Special:CentralAutoLogin\/start?useformat=desktop&type=1x1&usesul3=1)\n\nRetrieved from \"<https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&oldid=1341248860>\"\n\n[Categories](https:\/\/en.wikipedia.org\/wiki\/Help:Category \"Help:Category\"):\n\n- [Interferometric telescopes](https:\/\/en.wikipedia.org\/wiki\/Category:Interferometric_telescopes \"Category:Interferometric telescopes\")\n- [Albert Einstein Medal recipients](https:\/\/en.wikipedia.org\/wiki\/Category:Albert_Einstein_Medal_recipients \"Category:Albert Einstein Medal recipients\")\n\nHidden categories:\n\n- [Articles with short description](https:\/\/en.wikipedia.org\/wiki\/Category:Articles_with_short_description \"Category:Articles with short description\")\n- [Short description is different from Wikidata](https:\/\/en.wikipedia.org\/wiki\/Category:Short_description_is_different_from_Wikidata \"Category:Short description is different from Wikidata\")\n- [Use American English from April 2019](https:\/\/en.wikipedia.org\/wiki\/Category:Use_American_English_from_April_2019 \"Category:Use American English from April 2019\")\n- [All Wikipedia articles written in American English](https:\/\/en.wikipedia.org\/wiki\/Category:All_Wikipedia_articles_written_in_American_English \"Category:All Wikipedia articles written in American English\")\n- [Use mdy dates from April 2019](https:\/\/en.wikipedia.org\/wiki\/Category:Use_mdy_dates_from_April_2019 \"Category:Use mdy dates from April 2019\")\n- [Pages using infobox mapframe with missing coordinates](https:\/\/en.wikipedia.org\/wiki\/Category:Pages_using_infobox_mapframe_with_missing_coordinates \"Category:Pages using infobox mapframe with missing coordinates\")\n- [Articles using Infobox observatory using locally defined parameters](https:\/\/en.wikipedia.org\/wiki\/Category:Articles_using_Infobox_observatory_using_locally_defined_parameters \"Category:Articles using Infobox observatory using locally defined parameters\")\n- [Pages using multiple image with unknown parameters](https:\/\/en.wikipedia.org\/wiki\/Category:Pages_using_multiple_image_with_unknown_parameters \"Category:Pages using multiple image with unknown parameters\")\n- [Commons category link from Wikidata](https:\/\/en.wikipedia.org\/wiki\/Category:Commons_category_link_from_Wikidata \"Category:Commons category link from Wikidata\")\n\n- This page was last edited on 2 March 2026, at 04:38 (UTC).\n- Text is available under the [Creative Commons Attribution-ShareAlike 4.0 License](https:\/\/en.wikipedia.org\/wiki\/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License \"Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License\"); additional terms may apply. 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The EHT project combines data from several [very-long-baseline interferometry](https:\/\/en.wikipedia.org\/wiki\/Very-long-baseline_interferometry \"Very-long-baseline interferometry\") (VLBI) stations around Earth, which form a combined array with an [angular resolution](https:\/\/en.wikipedia.org\/wiki\/Angular_resolution \"Angular resolution\") sufficient to observe objects the size of a [supermassive black hole](https:\/\/en.wikipedia.org\/wiki\/Supermassive_black_hole \"Supermassive black hole\")'s [event horizon](https:\/\/en.wikipedia.org\/wiki\/Event_horizon \"Event horizon\"). The project's observational targets include the two [black holes](https:\/\/en.wikipedia.org\/wiki\/Black_hole \"Black hole\") with the largest [angular diameter](https:\/\/en.wikipedia.org\/wiki\/Angular_diameter \"Angular diameter\") as observed from Earth: the black hole at the center of the [supergiant](https:\/\/en.wikipedia.org\/wiki\/Type-cD_galaxy \"Type-cD galaxy\") [elliptical galaxy](https:\/\/en.wikipedia.org\/wiki\/Elliptical_galaxy \"Elliptical galaxy\") [Messier 87](https:\/\/en.wikipedia.org\/wiki\/Messier_87 \"Messier 87\"), and [Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\"), at [the center](https:\/\/en.wikipedia.org\/wiki\/Galactic_Center \"Galactic Center\") of the [Milky Way](https:\/\/en.wikipedia.org\/wiki\/Milky_Way \"Milky Way\").[\\[1\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-wp-2009-1)[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)\n\nThe Event Horizon Telescope project is an international collaboration that was launched in 2009[\\[1\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-wp-2009-1) after a long period of theoretical and technical developments. On the theory side, work on the photon orbit[\\[3\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-3) and first simulations of what a black hole would look like[\\[4\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-4) progressed to predictions of VLBI imaging for the Galactic Center black hole, Sgr A\\*.[\\[5\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:0-5)[\\[6\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:0a-6) Technical advances in radio observing moved from the first detection of Sgr A\\*,[\\[7\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-7) through VLBI at progressively shorter wavelengths, ultimately leading to detection of horizon scale structure in both Sgr A\\* and M87.[\\[8\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-Sheperd2008-8)[\\[9\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-Sheperd2012-9) The collaboration now comprises over 300[\\[10\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-breakthrough-prize-10) members, and 60 institutions, working in over 20 countries and regions.[\\[11\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-website-11)\n\nThe first image of a black hole, at the center of galaxy Messier 87, was published by the EHT Collaboration on April 10, 2019, in a series of six scientific publications.[\\[12\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eht-apjl-focus-12) The array made this observation at a wavelength of 1.3 mm and with a theoretical [diffraction-limited resolution](https:\/\/en.wikipedia.org\/wiki\/Diffraction-limited_resolution \"Diffraction-limited resolution\") of 25 [microarcseconds](https:\/\/en.wikipedia.org\/wiki\/Microarcsecond \"Microarcsecond\"). In March 2021, the Collaboration presented, for the first time, a [polarized-based image](https:\/\/en.wikipedia.org\/wiki\/Polarization_\\(waves\\) \"Polarization (waves)\") of the [black hole](https:\/\/en.wikipedia.org\/wiki\/Black_hole \"Black hole\") which may help better reveal the forces giving rise to [quasars](https:\/\/en.wikipedia.org\/wiki\/Quasar \"Quasar\").[\\[13\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20210324-13) Future plans involve improving the array's resolution by adding new telescopes and by taking shorter-wavelength observations.[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[14\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-aasnova-20190410-14) On 12 May 2022, astronomers unveiled the first image of the supermassive black hole at the center of the [Milky Way](https:\/\/en.wikipedia.org\/wiki\/Milky_Way \"Milky Way\"), [Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\").[\\[15\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20220512-15) Since 2018 the EHT has been capable of imaging at a wavelength of 870 μm (345 GHz), giving an angular resolution of 19 μas, the best resolution of any ground-based telescope.[\\[16\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-16)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/1\/13\/EHT-infography.png\/250px-EHT-infography.png)](https:\/\/en.wikipedia.org\/wiki\/File:EHT-infography.png)\n\nA schematic diagram of the VLBI mechanism of EHT. Each antenna, spread out over vast distances, has an extremely precise [atomic clock](https:\/\/en.wikipedia.org\/wiki\/Atomic_clock \"Atomic clock\"). [Analogue signals](https:\/\/en.wikipedia.org\/wiki\/Analog_signal \"Analog signal\") collected by the antenna are converted to [digital signals](https:\/\/en.wikipedia.org\/wiki\/Digital_signal \"Digital signal\") and stored on hard drives together with the time signals provided by the atomic clock. The hard drives are then shipped to a central location to be synchronized. An astronomical observation image is obtained by processing the data gathered from multiple locations.\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/2\/23\/EHTobservations2017.jpg\/250px-EHTobservations2017.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:EHTobservations2017.jpg)\n\nEHT observations during its 2017 M87 multiwavelength campaign decomposed by instrument from lower (EHT\/ALMA\/SMA) to higher (VERITAS) frequency. (Fermi-LAT in continuous survey mode) (dates also in [Modified Julian days](https:\/\/en.wikipedia.org\/wiki\/Julian_day#Variants \"Julian day\"))\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/7\/7e\/Sagittarius_A%2A.jpg\/250px-Sagittarius_A%2A.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:Sagittarius_A*.jpg)\n\nSoft [X-ray](https:\/\/en.wikipedia.org\/wiki\/X-ray \"X-ray\") image of [Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\") (center) and two [light echoes](https:\/\/en.wikipedia.org\/wiki\/Light_echo \"Light echo\") from a recent explosion (circled)\n\nThe EHT is composed of many radio observatories or radio-telescope facilities around the world, working together to produce a high-sensitivity, high-angular-resolution telescope. Through the technique of [very-long-baseline interferometry](https:\/\/en.wikipedia.org\/wiki\/Very-long-baseline_interferometry \"Very-long-baseline interferometry\") (VLBI), many independent radio antennas separated by hundreds or thousands of kilometres can act as a [phased array](https:\/\/en.wikipedia.org\/wiki\/Phased_array \"Phased array\"), a virtual telescope which can be pointed electronically, with an [effective aperture](https:\/\/en.wikipedia.org\/wiki\/Aperture_synthesis \"Aperture synthesis\") which is the diameter of the entire planet, substantially improving its angular resolution.[\\[17\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-O'Neil2015-17) The effort includes development and deployment of [submillimeter](https:\/\/en.wikipedia.org\/wiki\/Submillimetre_astronomy \"Submillimetre astronomy\") dual [polarization](https:\/\/en.wikipedia.org\/wiki\/Polarization_\\(waves\\) \"Polarization (waves)\") receivers, highly stable frequency standards to enable very-long-baseline interferometry at 230–450 GHz, higher-bandwidth VLBI backends and recorders, as well as commissioning of new submillimeter VLBI sites.[\\[18\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-18)\n\nEach year since its first data capture in 2006, the EHT array has moved to add more observatories to its global network of radio telescopes. The first image of the Milky Way's supermassive black hole, Sagittarius A\\*, was expected to be produced from data taken in April 2017,[\\[19\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-19)[\\[20\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-nature543-20) but because there are no flights in or out of the South Pole during austral winter (April to October), the full data set could not be processed until December 2017, when the shipment of data from the [South Pole Telescope](https:\/\/en.wikipedia.org\/wiki\/South_Pole_Telescope \"South Pole Telescope\") arrived.[\\[21\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-21)\n\nData collected on hard drives are transported by commercial freight airplanes[\\[22\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-22) (a so-called [sneakernet](https:\/\/en.wikipedia.org\/wiki\/Sneakernet \"Sneakernet\")) from the various telescopes to the [MIT](https:\/\/en.wikipedia.org\/wiki\/MIT \"MIT\") [Haystack Observatory](https:\/\/en.wikipedia.org\/wiki\/Haystack_Observatory \"Haystack Observatory\") and the [Max Planck Institute for Radio Astronomy](https:\/\/en.wikipedia.org\/wiki\/Max_Planck_Institute_for_Radio_Astronomy \"Max Planck Institute for Radio Astronomy\"), where the data are [cross-correlated](https:\/\/en.wikipedia.org\/wiki\/Cross-correlation \"Cross-correlation\") and analyzed on a [grid computer](https:\/\/en.wikipedia.org\/wiki\/Grid_computing \"Grid computing\") made from about 800 [CPUs](https:\/\/en.wikipedia.org\/wiki\/Central_processing_unit \"Central processing unit\") all connected through a 40 Gbit\/s network.[\\[23\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-23)\n\nBecause of the [COVID-19 pandemic](https:\/\/en.wikipedia.org\/wiki\/COVID-19_pandemic \"COVID-19 pandemic\"), weather patterns, and celestial mechanics, the 2020 observational campaign was postponed to March 2021.[\\[24\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-24)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/a\/a9\/Event_Horizon_Telescope_and_Apollo_16.png\/250px-Event_Horizon_Telescope_and_Apollo_16.png)](https:\/\/en.wikipedia.org\/wiki\/File:Event_Horizon_Telescope_and_Apollo_16.png)\n\nA series of images descriptive of the level of magnification achieved by the EHT (akin to seeing, from the Earth's surface, an object the size of a tennis ball on the Moon); starts at top-left image and moves counter−clockwise to finish at top-right corner\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/4\/4f\/Black_hole_-_Messier_87_crop_max_res.jpg\/250px-Black_hole_-_Messier_87_crop_max_res.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:Black_hole_-_Messier_87_crop_max_res.jpg)\n\nImage of [M87\\*](https:\/\/en.wikipedia.org\/wiki\/M87* \"M87*\") generated from data gathered by the Event Horizon Telescope[\\[25\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20190410-25)[\\[26\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NASA-20190410-26)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/b\/bf\/A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif\/lossy-page1-250px-A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif)\n\nA view of [M87\\*](https:\/\/en.wikipedia.org\/wiki\/M87* \"M87*\") black hole in polarised light\n\nThe Event Horizon Telescope Collaboration announced its first results in six simultaneous press conferences worldwide on April 10, 2019.[\\[25\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20190410-25)[\\[26\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NASA-20190410-26)[\\[27\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-27) The announcement featured the first direct image of a black hole, which showed the [supermassive black hole](https:\/\/en.wikipedia.org\/wiki\/Supermassive_black_hole \"Supermassive black hole\") at the center of [Messier 87](https:\/\/en.wikipedia.org\/wiki\/Messier_87 \"Messier 87\"), designated M87\\*.[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[28\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NS-name-28)[\\[29\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20190412-29) The scientific results were presented in a series of six papers published in *[The Astrophysical Journal Letters](https:\/\/en.wikipedia.org\/wiki\/The_Astrophysical_Journal_Letters \"The Astrophysical Journal Letters\")*.[\\[30\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eso1907-30) A clockwise [rotating black hole](https:\/\/en.wikipedia.org\/wiki\/Rotating_black_hole \"Rotating black hole\") was observed in the 6σ region.[\\[31\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-RotBlackHole-31)\n\nThe image provided a test for [Albert Einstein](https:\/\/en.wikipedia.org\/wiki\/Albert_Einstein \"Albert Einstein\")'s [general theory of relativity](https:\/\/en.wikipedia.org\/wiki\/General_relativity \"General relativity\") under extreme conditions.[\\[17\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-O'Neil2015-17)[\\[20\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-nature543-20) Studies have previously tested general relativity by looking at the motions of stars and gas clouds near the edge of a black hole. However, an image of a black hole brings observations even closer to the event horizon.[\\[32\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-sciencenews-32) Relativity predicts a dark shadow-like region, caused by gravitational bending and capture of light,[\\[5\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:0-5)[\\[6\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:0a-6) which matches the observed image. The published paper states: \"Overall, the observed image is consistent with expectations for the shadow of a [spinning Kerr black hole](https:\/\/en.wikipedia.org\/wiki\/Spinning_Kerr_black_hole \"Spinning Kerr black hole\") as predicted by general relativity.\"[\\[33\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-33) Paul T. P. Ho, EHT Board member, said: \"Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter, and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well.\"[\\[30\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eso1907-30)\n\nThe image also provided new measurements for the mass and diameter of M87\\*. EHT measured the black hole's mass to be 6\\.5±0\\.7 billion [solar masses](https:\/\/en.wikipedia.org\/wiki\/Solar_masses \"Solar masses\") and measured the diameter of its event horizon to be approximately 40 billion kilometres (270 AU; 0.0013 pc; 0.0042 ly), roughly 2.5 times smaller than the shadow that it casts, seen at the center of the image.[\\[30\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-eso1907-30)[\\[32\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-sciencenews-32) Previous observations of M87 showed that the large-scale [jet](https:\/\/en.wikipedia.org\/wiki\/Astrophysical_jet \"Astrophysical jet\") is inclined at an angle of 17° relative to the observer's line of sight and oriented on the plane of the sky at a [position angle](https:\/\/en.wikipedia.org\/wiki\/Position_angle \"Position angle\") of −72°.[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[34\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-34) From the enhanced brightness of the southern part of the ring due to [relativistic beaming](https:\/\/en.wikipedia.org\/wiki\/Relativistic_beaming \"Relativistic beaming\") of approaching funnel wall jet emission, EHT concluded the black hole, which anchors the jet, spins clockwise, as seen from Earth.[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[14\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-aasnova-20190410-14) EHT simulations allow for both prograde and retrograde inner disk rotation with respect to the black hole, while excluding zero black hole spin using a conservative minimum jet power of 1042 erg\/s via the [Blandford–Znajek process](https:\/\/en.wikipedia.org\/wiki\/Blandford%E2%80%93Znajek_process \"Blandford–Znajek process\").[\\[2\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\\[35\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-35)\n\nProducing an image from data from an array of radio telescopes requires much mathematical work. Four independent teams created images to assess the reliability of the results.[\\[36\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-imaging-36) These methods included both an established algorithm in [radio astronomy](https:\/\/en.wikipedia.org\/wiki\/Radio_astronomy \"Radio astronomy\") for [image reconstruction](https:\/\/en.wikipedia.org\/wiki\/Image_reconstruction \"Image reconstruction\") known as [CLEAN](https:\/\/en.wikipedia.org\/wiki\/CLEAN_\\(algorithm\\) \"CLEAN (algorithm)\"), invented by [Jan Högbom](https:\/\/en.wikipedia.org\/wiki\/Jan_H%C3%B6gbom \"Jan Högbom\"),[\\[37\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-H%C3%B6gbom1974-37) as well as self-calibrating [image processing](https:\/\/en.wikipedia.org\/wiki\/Image_processing \"Image processing\") methods[\\[38\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-bnss,etc-38) for astronomy such as the [CHIRP algorithm](https:\/\/en.wikipedia.org\/wiki\/CHIRP_\\(algorithm\\) \"CHIRP (algorithm)\") created by [Katherine Bouman](https:\/\/en.wikipedia.org\/wiki\/Katherine_Bouman \"Katherine Bouman\") and others.[\\[36\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-imaging-36)[\\[39\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-39) The algorithms that were ultimately used were a [regularized](https:\/\/en.wikipedia.org\/wiki\/Regularization_\\(mathematics\\) \"Regularization (mathematics)\") [maximum likelihood](https:\/\/en.wikipedia.org\/wiki\/Maximum_likelihood \"Maximum likelihood\") (RML)[\\[40\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-40) algorithm and the [CLEAN](https:\/\/en.wikipedia.org\/wiki\/CLEAN_\\(algorithm\\) \"CLEAN (algorithm)\") algorithm.[\\[36\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-imaging-36)\n\nIn March 2020, astronomers proposed an improved way of seeing more of the rings in the first black hole image.[\\[41\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-NYT-20200328-41)[\\[42\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-42) In March 2021, a new photo was revealed, showing how the M87 black hole looks in polarised light. This is the first time astronomers have been able to measure polarisation so close to the edge of a black hole. The lines on the photo mark the orientation of polarisation, which is related to the magnetic field around the shadow of the black hole.[\\[43\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-43)\n\nIn August 2022, a team led by [University of Waterloo](https:\/\/en.wikipedia.org\/wiki\/University_of_Waterloo \"University of Waterloo\") researcher Avery Broderick released a \"remaster\\[ed\\]\" version of original image generated from the data collected by the EHT. This image \"resolve\\[d\\] a fundamental signature of gravity around a black hole\", with it showing a displaying [photon ring](https:\/\/en.wikipedia.org\/wiki\/Photon_ring \"Photon ring\") around [M87\\*](https:\/\/en.wikipedia.org\/wiki\/M87* \"M87*\").[\\[44\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-44)[\\[45\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-45) The claim has been subsequently disputed.[\\[46\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-46)\n\nIn 2023, EHT released new, sharper images of the M87 black hole, reconstructed from the same 2017 data but created using the PRIMO algorithm.[\\[47\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-47)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/d\/d7\/EHT3C279PressReleaseImage.png\/250px-EHT3C279PressReleaseImage.png)](https:\/\/en.wikipedia.org\/wiki\/File:EHT3C279PressReleaseImage.png)\n\nEHT image of the archetypal blazar 3C 279 showing a relativistic jet down to the AGN core surrounding the supermassive black hole.\n\nIn April 2020, the EHT released the first 20 microarcsecond resolution images of the archetypal [blazar](https:\/\/en.wikipedia.org\/wiki\/Blazar \"Blazar\") [3C 279](https:\/\/en.wikipedia.org\/wiki\/3C_279 \"3C 279\") it observed in April 2017.[\\[48\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-EHT3C279-48) These images, generated from observations over 4 nights in April 2017, reveal bright components of a jet whose projection on the observer plane exhibit apparent [superluminal motions](https:\/\/en.wikipedia.org\/wiki\/Superluminal_motion \"Superluminal motion\") with speeds up to 20 *c*.[\\[49\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-EHT3C279PressRelease-49) Such apparent superluminal motion from relativistic emitters such as an approaching jet is explained by emission originating closer to the observer (downstream along the jet) catching up with emission originating further from the observer (at the jet base) as the jet propagates close to the speed of light at small angles to the line of sight.\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/6\/61\/EHTcentaurusA2021.jpg\/250px-EHTcentaurusA2021.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:EHTcentaurusA2021.jpg)\n\nImage of Centaurus A showing its black hole jet at different scales\n\nIn July 2021, high resolution images of the jet produced by a supermassive black hole sitting at the center of [Centaurus A](https:\/\/en.wikipedia.org\/wiki\/Centaurus_A \"Centaurus A\") were released. With a mass around 5\\.5×107 [M☉](https:\/\/en.wikipedia.org\/wiki\/Solar_mass \"Solar mass\"), the black hole is not large enough for its [photon sphere](https:\/\/en.wikipedia.org\/wiki\/Photon_sphere \"Photon sphere\") to be observed, as in EHT images of Messier M87\\*, but its jet extends even beyond its host galaxy while staying as a highly collimated beam which is a point of study. Edge-brightening of the jet was also observed which would exclude models of particle acceleration that are unable to reproduce this effect. The image was 16 times sharper than previous observations and utilized a 1.3 mm wavelength.[\\[50\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-50)[\\[51\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-51)[\\[52\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-52)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/9\/96\/EHT_Saggitarius_A_black_hole.tif\/lossy-page1-200px-EHT_Saggitarius_A_black_hole.tif.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:EHT_Saggitarius_A_black_hole.tif)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/3\/3e\/Sagittarius_Astar_in_polarised_light.tif\/lossy-page1-200px-Sagittarius_Astar_in_polarised_light.tif.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:Sagittarius_Astar_in_polarised_light.tif)\n\nSagittarius A\\* in polarised light, image released in 2024\n\nOn May 12, 2022, the EHT Collaboration revealed an image of [Sagittarius A\\*](https:\/\/en.wikipedia.org\/wiki\/Sagittarius_A* \"Sagittarius A*\"), the supermassive black hole at the [center](https:\/\/en.wikipedia.org\/wiki\/Galactic_Center \"Galactic Center\") of the [Milky Way](https:\/\/en.wikipedia.org\/wiki\/Milky_Way \"Milky Way\") [galaxy](https:\/\/en.wikipedia.org\/wiki\/Galaxy \"Galaxy\"). The black hole is 27,000 light-years away from Earth; it is thousands of times smaller than M87\\*. [Sera Markoff](https:\/\/en.wikipedia.org\/wiki\/Sera_Markoff \"Sera Markoff\"), Co-Chair of the EHT Science Council, said: \"We have two completely different types of galaxies and two very different black hole masses, but close to the edge of these black holes they look amazingly similar. This tells us that General Relativity governs these objects up close, and any differences we see further away must be due to differences in the material that surrounds the black holes.\"[\\[53\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-53)\n\nOn March 22, 2024, the EHT Collaboration released an image of Sagittarius A\\* in polarized light.[\\[54\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-54)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/e\/e7\/EHTj1924-2914.png\/250px-EHTj1924-2914.png)](https:\/\/en.wikipedia.org\/wiki\/File:EHTj1924-2914.png)\n\nA multifrequency view of the bent jet in Blazar J1924-2914.[\\[55\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:1-55)[\\[56\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:2-56)\n\nIn August 2022, the EHT together with Global Millimeter VLBI Array and the [Very Long Baseline Array](https:\/\/en.wikipedia.org\/wiki\/Very_Long_Baseline_Array \"Very Long Baseline Array\") imaged the distant [blazar](https:\/\/en.wikipedia.org\/wiki\/Blazar \"Blazar\") J1924-2914. They operated at 230 GHz, 86 GHz and 2.3+8.7 GHz, respectively, the highest angular resolution images of polarized emission from a quasar ever obtained. Observations reveal a helically bent jet and the polarization of its emission suggest a toroidal magnetic field structure. The object is used as calibrator for Sagittarius A\\* sharing strong optical variability and polarization with it.[\\[55\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:1-55)[\\[56\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-:2-56)\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/3\/3b\/NRAO_530_by_EHT_01.jpg\/250px-NRAO_530_by_EHT_01.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:NRAO_530_by_EHT_01.jpg)\n\nNRAO 530 by EHT. The total intensity is shown in grayscale with black contours indicating 10%, 25%, 50%, and 75% of the peak LP intensity. Black dotted contours indicate 25%, 50%, and 75% of the peak polarized intensity.\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/7\/77\/NRAO_530_by_EHT_02.jpg\/250px-NRAO_530_by_EHT_02.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:NRAO_530_by_EHT_02.jpg)\n\nSchematic of the total-intensity and LP components in the EHT fiducial image of NRAO 530; white contours show the total intensity levels; color scale and cyan contours represent the polarized intensity of the method-averaged image.\n\nIn February 2023, the EHT reported on the observations of the [quasar](https:\/\/en.wikipedia.org\/wiki\/Quasar \"Quasar\") NRAO 530. NRAO 530 (1730−130, J1733−1304) is a [flat-spectrum radio quasar](https:\/\/en.wikipedia.org\/wiki\/Flat-spectrum_radio_quasar \"Flat-spectrum radio quasar\") (FSRQ) that belongs to the class of bright γ-ray [blazars](https:\/\/en.wikipedia.org\/wiki\/Blazar \"Blazar\") and shows significant variability across the entire electromagnetic spectrum. The source was monitored by the University of Michigan Radio Observatory at 4.8, 8.4, and 14.5 GHz for several decades until 2012. The quasar underwent a dramatic radio outburst in 1997, during which its flux density at 14.5 GHz exceeded 10 Jy, while the average value is ~2 Jy. Since 2002, NRAO 530 has been monitored by the Submillimeter Array (SMA; Maunakea, Hawaii) at 1.3 mm and 870 μm. NRAO 530 has a redshift of *z* = 0.902 (Junkkarinen 1984), for which 100 μas corresponds to a linear distance of 6 billion pc. The source contains a supermassive black hole, the mass of which is currently uncertain, with estimates ranging from 3×108 *M*☉ to 2×109 *M*☉.[\\[57\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-nrao530-57)\n\nIt was observed with the Event Horizon Telescope on April 5−7, 2017, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A\\*. The observations were performed with the full EHT 2017 array of eight telescopes located at six geographical sites. At *z* = 0.902, this is the most distant object imaged by the EHT so far. The team reconstructed the first images of the source at 230 GHz, at an angular resolution of about 20 μas, both in total intensity and in linear polarization (LP). Source variability was not detected, that allowed to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which was associated with the core. The feature is linearly polarized, with a fractional polarization of about 5%–8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle about −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field.[\\[57\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-nrao530-57)\n\n## Collaborating institutes\n\\[[edit](https:\/\/en.wikipedia.org\/w\/index.php?title=Event_Horizon_Telescope&action=edit&section=9 \"Edit section: Collaborating institutes\")\\]\n\nThe EHT Collaboration consists of 13 stakeholder institutes:[\\[58\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-58)\n\n- the [Academia Sinica](https:\/\/en.wikipedia.org\/wiki\/Academia_Sinica \"Academia Sinica\") Institute of Astronomy and Astrophysics\n- the [University of Arizona](https:\/\/en.wikipedia.org\/wiki\/University_of_Arizona \"University of Arizona\")\n- the [University of Chicago](https:\/\/en.wikipedia.org\/wiki\/University_of_Chicago \"University of Chicago\")\n- the [East Asian Observatory](https:\/\/en.wikipedia.org\/w\/index.php?title=East_Asian_Observatory&action=edit&redlink=1 \"East Asian Observatory (page does not exist)\")\n- [Goethe University Frankfurt](https:\/\/en.wikipedia.org\/wiki\/Goethe_University_Frankfurt \"Goethe University Frankfurt\")\n- [Smithsonian Astrophysical Observatory](https:\/\/en.wikipedia.org\/wiki\/Smithsonian_Astrophysical_Observatory \"Smithsonian Astrophysical Observatory\") (part of the [Harvard–Smithsonian Center for Astrophysics](https:\/\/en.wikipedia.org\/wiki\/Harvard%E2%80%93Smithsonian_Center_for_Astrophysics \"Harvard–Smithsonian Center for Astrophysics\"))\n- [Institut de radioastronomie millimétrique](https:\/\/en.wikipedia.org\/wiki\/Institut_de_radioastronomie_millim%C3%A9trique \"Institut de radioastronomie millimétrique\") (IRAM, itself a collaboration between the French [CNRS](https:\/\/en.wikipedia.org\/wiki\/CNRS \"CNRS\"), the German [Max Planck Society](https:\/\/en.wikipedia.org\/wiki\/Max_Planck_Society \"Max Planck Society\"), and the Spanish [Instituto Geográfico Nacional](https:\/\/en.wikipedia.org\/wiki\/Instituto_Geogr%C3%A1fico_Nacional_\\(Spain\\) \"Instituto Geográfico Nacional (Spain)\"))\n- [Large Millimeter Telescope](https:\/\/en.wikipedia.org\/wiki\/Large_Millimeter_Telescope \"Large Millimeter Telescope\") Alfonso Serrano\n- [Max Planck Institute for Radio Astronomy](https:\/\/en.wikipedia.org\/wiki\/Max_Planck_Institute_for_Radio_Astronomy \"Max Planck Institute for Radio Astronomy\")\n- [MIT](https:\/\/en.wikipedia.org\/wiki\/MIT \"MIT\") [Haystack Observatory](https:\/\/en.wikipedia.org\/wiki\/Haystack_Observatory \"Haystack Observatory\")\n- [National Astronomical Observatory of Japan](https:\/\/en.wikipedia.org\/wiki\/National_Astronomical_Observatory_of_Japan \"National Astronomical Observatory of Japan\")\n- [Perimeter Institute for Theoretical Physics](https:\/\/en.wikipedia.org\/wiki\/Perimeter_Institute_for_Theoretical_Physics \"Perimeter Institute for Theoretical Physics\")\n- [Radboud University](https:\/\/en.wikipedia.org\/wiki\/Radboud_University \"Radboud University\")\n\n[![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/1\/10\/Locations_of_the_telescopes_that_make_up_the_EHT_array_%28eso2208-eht-mwi%29.tiff\/lossy-page1-1000px-Locations_of_the_telescopes_that_make_up_the_EHT_array_%28eso2208-eht-mwi%29.tiff.jpg)](https:\/\/en.wikipedia.org\/wiki\/File:Locations_of_the_telescopes_that_make_up_the_EHT_array_\\(eso2208-eht-mwi\\).tiff)\n\nLocations of the telescopes that make up the EHT array. A global map showing the radio observatories that form the Event Horizon Telescope (EHT) network used to image the Milky Way's central black hole, Sagittarius A\\*. The telescopes highlighted in yellow were part of the EHT network during the observations of Sagittarius A\\* in 2017. These include the Atacama Large Millimeter\/submillimeter Array (ALMA), the Atacama Pathfinder EXperiment (APEX), IRAM 30-meter telescope (30-M), James Clark Maxwell Telescope (JCMT), Large Millimeter Telescope (LMT), Submillimeter Array (SMA), Submillimetere Telescope (SMT) and South Pole Telescope (SPT). Highlighted in blue are the three telescopes added to the EHT Collaboration after 2018: the Greenland Telescope (GLT), the NOrthern Extended Millimeter Array (NOEMA) in France, and the University of Arizona ARO 12-meter Telescope at Kitt Peak.\n\nThe EHT Collaboration receives funding from numerous sources including:[\\[59\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-59)\n\n- [United States National Science Foundation](https:\/\/en.wikipedia.org\/wiki\/National_Science_Foundation \"National Science Foundation\")\n- [European Research Council](https:\/\/en.wikipedia.org\/wiki\/European_Research_Council \"European Research Council\")\n- [National Science and Technology Council of Taiwan](https:\/\/en.wikipedia.org\/wiki\/National_Science_and_Technology_Council_\\(Taiwan\\) \"National Science and Technology Council (Taiwan)\") (formerly Ministry of Science and Technology of Taiwan)\n- [Max Planck Society](https:\/\/en.wikipedia.org\/wiki\/Max_Planck_Society \"Max Planck Society\")\n- [Consejo Nacional de Ciencia y Technologia, Mexico](https:\/\/en.wikipedia.org\/wiki\/Consejo_Nacional_de_Ciencia_y_Tecnolog%C3%ADa_\\(Mexico\\) \"Consejo Nacional de Ciencia y Tecnología (Mexico)\")\n- [John Templeton Foundation](https:\/\/en.wikipedia.org\/wiki\/John_Templeton_Foundation \"John Templeton Foundation\")\n- [Gordon and Betty Moore Foundation](https:\/\/en.wikipedia.org\/wiki\/Gordon_and_Betty_Moore_Foundation \"Gordon and Betty Moore Foundation\")\n- [Japan Society for the Promotion of Science](https:\/\/en.wikipedia.org\/wiki\/Japan_Society_for_the_Promotion_of_Science \"Japan Society for the Promotion of Science\")\n- [Natural Sciences and Engineering Research Council of Canada](https:\/\/en.wikipedia.org\/wiki\/Natural_Sciences_and_Engineering_Research_Council \"Natural Sciences and Engineering Research Council\")\n- [Academia Sinica](https:\/\/en.wikipedia.org\/wiki\/Academia_Sinica \"Academia Sinica\")\n- [Smithsonian Institution](https:\/\/en.wikipedia.org\/wiki\/Smithsonian_Institution \"Smithsonian Institution\")\n\nAdditionally, [Western Digital](https:\/\/en.wikipedia.org\/wiki\/Western_Digital \"Western Digital\") and [Xilinx](https:\/\/en.wikipedia.org\/wiki\/Xilinx \"Xilinx\") are industry donors.[\\[60\\]](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_note-60)\n\n1. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-eht-wp-2009_1-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-eht-wp-2009_1-1)\n   Doeleman, Sheperd (June 21, 2009). \"Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole\". *Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers*. **2010**: 68. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[0906\\.3899](https:\/\/arxiv.org\/abs\/0906.3899). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2009astro2010S..68D](https:\/\/ui.adsabs.harvard.edu\/abs\/2009astro2010S..68D).\n2. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-1) [***c***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-2) [***d***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-3) [***e***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-4) [***f***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-5)\n   The Event Horizon Telescope Collaboration (April 10, 2019). [\"First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole\"](https:\/\/doi.org\/10.3847%2F2041-8213%2Fab0ec7). *[The Astrophysical Journal Letters](https:\/\/en.wikipedia.org\/wiki\/The_Astrophysical_Journal_Letters \"The Astrophysical Journal Letters\")*. **875** (1): L1. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[1906\\.11238](https:\/\/arxiv.org\/abs\/1906.11238). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2019ApJ...875L...1E](https:\/\/ui.adsabs.harvard.edu\/abs\/2019ApJ...875L...1E). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.3847\/2041-8213\/ab0ec7](https:\/\/doi.org\/10.3847%2F2041-8213%2Fab0ec7). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [145906806](https:\/\/api.semanticscholar.org\/CorpusID:145906806).\n3. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-3)**\n   Bardeen, James (1973). \"Black holes. Edited by C. DeWitt and B. S. DeWitt\". *Les Houches École d'Été de Physique Théorique*. [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[1973blho.conf.....D](https:\/\/ui.adsabs.harvard.edu\/abs\/1973blho.conf.....D).\n4. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-4)**\n   Luminet, Jean-Pierre (July 31, 1979). \"Image of a spherical black hole with thin accretion disk\". *Astronomy and Astrophysics*. **75**: 228. [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[1979A\\&A....75..228L](https:\/\/ui.adsabs.harvard.edu\/abs\/1979A&A....75..228L).\n5. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:0_5-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:0_5-1)\n   Falcke, Heino; Melia, Fulvio; Agol, Eric (January 1, 2000). \"Viewing the Shadow of the Black Hole at the Galactic Center\". *The Astrophysical Journal Letters*. **528** (1): L13–L16. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[astro-ph\/9912263](https:\/\/arxiv.org\/abs\/astro-ph\/9912263). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2000ApJ...528L..13F](https:\/\/ui.adsabs.harvard.edu\/abs\/2000ApJ...528L..13F). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1086\/312423](https:\/\/doi.org\/10.1086%2F312423). [PMID](https:\/\/en.wikipedia.org\/wiki\/PMID_\\(identifier\\) \"PMID (identifier)\") [10587484](https:\/\/pubmed.ncbi.nlm.nih.gov\/10587484). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [119433133](https:\/\/api.semanticscholar.org\/CorpusID:119433133).\n6. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:0a_6-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:0a_6-1)\n   Broderick, Avery; Loeb, Abraham (April 11, 2006). [\"Imaging optically-thin hotspots near the black hole horizon of Sgr A\\* at radio and near-infrared wavelengths\"](https:\/\/doi.org\/10.1111%2Fj.1365-2966.2006.10152.x). *Monthly Notices of the Royal Astronomical Society*. **367** (3): 905–916\\. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[astro-ph\/0509237](https:\/\/arxiv.org\/abs\/astro-ph\/0509237). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2006MNRAS.367..905B](https:\/\/ui.adsabs.harvard.edu\/abs\/2006MNRAS.367..905B). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1111\/j.1365-2966.2006.10152.x](https:\/\/doi.org\/10.1111%2Fj.1365-2966.2006.10152.x). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [16881360](https:\/\/api.semanticscholar.org\/CorpusID:16881360).\n7. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-7)**\n   Balick, Bruce; Brown, R.L. (December 1, 1974). [\"Intense sub-arcsecond structure in the galactic center\"](https:\/\/doi.org\/10.1086%2F153242). *The Astrophysical Journal*. **194** (1): 265–279\\. [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[1974ApJ...194..265B](https:\/\/ui.adsabs.harvard.edu\/abs\/1974ApJ...194..265B). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1086\/153242](https:\/\/doi.org\/10.1086%2F153242). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [121802758](https:\/\/api.semanticscholar.org\/CorpusID:121802758).\n8. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-Sheperd2008_8-0)**\n   Doeleman, Sheperd (September 4, 2008). \"Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre\". *Nature*. **455** (7209): 78–80\\. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[0809\\.2442](https:\/\/arxiv.org\/abs\/0809.2442). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2008Natur.455...78D](https:\/\/ui.adsabs.harvard.edu\/abs\/2008Natur.455...78D). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1038\/nature07245](https:\/\/doi.org\/10.1038%2Fnature07245). [PMID](https:\/\/en.wikipedia.org\/wiki\/PMID_\\(identifier\\) \"PMID (identifier)\") [18769434](https:\/\/pubmed.ncbi.nlm.nih.gov\/18769434). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [4424735](https:\/\/api.semanticscholar.org\/CorpusID:4424735).\n9. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-Sheperd2012_9-0)**\n   Doeleman, Sheperd (October 19, 2012). \"Jet-launching structure resolved near the supermassive black hole in M87\". *Science*. **338** (6105): 355–358\\. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[1210\\.6132](https:\/\/arxiv.org\/abs\/1210.6132). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2012Sci...338..355D](https:\/\/ui.adsabs.harvard.edu\/abs\/2012Sci...338..355D). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1126\/science.1224768](https:\/\/doi.org\/10.1126%2Fscience.1224768). [PMID](https:\/\/en.wikipedia.org\/wiki\/PMID_\\(identifier\\) \"PMID (identifier)\") [23019611](https:\/\/pubmed.ncbi.nlm.nih.gov\/23019611). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [37585603](https:\/\/api.semanticscholar.org\/CorpusID:37585603).\n10. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-eht-breakthrough-prize_10-0)**\n    [\"Winners Of The 2020 Breakthrough Prize In Life Sciences, Fundamental Physics And Mathematics Announced\"](https:\/\/breakthroughprize.org\/News\/54). *Breakthrough Prize*. Retrieved March 15, 2020.\n11. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-eht-website_11-0)**\n    [\"Event Horizon Telescope 2022\"](https:\/\/www.mpifr-bonn.mpg.de\/announcements\/2022\/2). March 12, 2022.\n12. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-eht-apjl-focus_12-0)**\n    Shep Doeleman, on behalf of the EHT Collaboration (April 2019). [\"Focus on the First Event Horizon Telescope Results\"](https:\/\/iopscience.iop.org\/journal\/2041-8205\/page\/Focus_on_EHT). *The Astrophysical Journal Letters*. Retrieved April 10, 2019.\n13. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-NYT-20210324_13-0)**\n    [Overbye, Dennis](https:\/\/en.wikipedia.org\/wiki\/Dennis_Overbye \"Dennis Overbye\") (March 24, 2021). [\"The Most Intimate Portrait Yet of a Black Hole – Two years of analyzing the polarized light from a galaxy's giant black hole has given scientists a glimpse at how quasars might arise\"](https:\/\/www.nytimes.com\/2021\/03\/24\/science\/astronomy-messier-87-black-hole.html). *[The New York Times](https:\/\/en.wikipedia.org\/wiki\/The_New_York_Times \"The New York Times\")*. Retrieved March 25, 2021.\n14. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-aasnova-20190410_14-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-aasnova-20190410_14-1)\n    Kohler, Susanna (April 10, 2019). [\"First Images of a Black Hole from the Event Horizon Telescope\"](https:\/\/aasnova.org\/2019\/04\/10\/first-images-of-a-black-hole-from-the-event-horizon-telescope\/). AAS Nova. Retrieved April 10, 2019.\n15. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-NYT-20220512_15-0)**\n    [Overbye, Dennis](https:\/\/en.wikipedia.org\/wiki\/Dennis_Overbye \"Dennis Overbye\") (May 12, 2022). [\"Has the Milky Way's Black Hole Come to Light? – The Event Horizon Telescope reaches again for a glimpse of the 'unseeable'\"](https:\/\/www.nytimes.com\/2022\/05\/12\/science\/black-hole-photo.html). *[The New York Times](https:\/\/en.wikipedia.org\/wiki\/The_New_York_Times \"The New York Times\")*. Retrieved May 12, 2022.\n16. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-16)** Alexander W. Raymond et al 2024 AJ 168 130\n17. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-O'Neil2015_17-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-O'Neil2015_17-1)\n    O'Neill, Ian (July 2, 2015). [\"Event Horizon Telescope Will Probe Spacetime's Mysteries\"](https:\/\/web.archive.org\/web\/20150905193743\/http:\/\/news.discovery.com\/space\/astronomy\/event-horizon-telescope-will-probe-spacetimes-mysteries-150702.htm). *Discovery News*. Archived from [the original](http:\/\/news.discovery.com\/space\/astronomy\/event-horizon-telescope-will-probe-spacetimes-mysteries-150702.htm) on September 5, 2015. Retrieved August 21, 2015.\n18. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-18)**\n    [\"MIT Haystack Observatory: Astronomy Wideband VLBI Millimeter Wavelength\"](https:\/\/www.haystack.mit.edu\/ast\/uvlbi\/mm\/eht.html). *www.haystack.mit.edu*.\n19. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-19)**\n    Webb, Jonathan (January 8, 2016). [\"Event horizon snapshot due in 2017\"](https:\/\/www.bbc.com\/news\/science-environment-35258378). *BBC News*. Retrieved March 24, 2016.\n20. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-nature543_20-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-nature543_20-1)\n    Davide Castelvecchi (March 23, 2017). [\"How to hunt for a black hole with a telescope the size of Earth\"](https:\/\/doi.org\/10.1038%2F543478a). *Nature*. **543** (7646): 478–480\\. [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2017Natur.543..478C](https:\/\/ui.adsabs.harvard.edu\/abs\/2017Natur.543..478C). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1038\/543478a](https:\/\/doi.org\/10.1038%2F543478a). [PMID](https:\/\/en.wikipedia.org\/wiki\/PMID_\\(identifier\\) \"PMID (identifier)\") [28332538](https:\/\/pubmed.ncbi.nlm.nih.gov\/28332538).\n21. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-21)**\n    [\"EHT Status Update, December 15 2017\"](http:\/\/eventhorizontelescope.org\/blog\/eht-status-update-december-15-2017). *eventhorizontelescope.org*. December 15, 2017. Retrieved February 9, 2018.\n22. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-22)**\n    [\"The Hidden Shipping and Handling Behind That Black-Hole Picture\"](https:\/\/www.theatlantic.com\/science\/archive\/2019\/04\/black-hole-hard-disks-picture\/587119\/). *The Atlantic*. April 13, 2019. Retrieved April 14, 2019.\n23. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-23)**\n    Mearian, Lucas (August 18, 2015). [\"Massive telescope array aims for black hole, gets gusher of data\"](http:\/\/www.computerworld.com\/article\/2972251\/space-technology\/massive-telescope-array-aims-for-black-hole-gets-gusher-of-data.html). *Computerworld*. Retrieved August 21, 2015.\n24. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-24)**\n    [\"EHT Observing Campaign 2020 Canceled Due to the COVID-19 Outbreak\"](https:\/\/eventhorizontelescope.org\/blog\/eht-observing-campaign-2020-canceled-due-covid-19-outbreak). *eventhorizontelescope.org*. March 17, 2020. Retrieved March 29, 2020.\n25. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-NYT-20190410_25-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-NYT-20190410_25-1)\n    [Overbye, Dennis](https:\/\/en.wikipedia.org\/wiki\/Dennis_Overbye \"Dennis Overbye\") (April 10, 2019). [\"Black Hole Picture Revealed for the First Time\"](https:\/\/www.nytimes.com\/2019\/04\/10\/science\/black-hole-picture.html?comments#permid=31473598). *[The New York Times](https:\/\/en.wikipedia.org\/wiki\/The_New_York_Times \"The New York Times\")*. 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[doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.3847\/1538-4357\/aaafcc](https:\/\/doi.org\/10.3847%2F1538-4357%2Faaafcc). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [59322635](https:\/\/api.semanticscholar.org\/CorpusID:59322635).\n35. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-35)**\n    Blandford, R. D.; Znajek, R. L. (1977). [\"Electromagnetic extraction of energy from Kerr black holes\"](https:\/\/doi.org\/10.1093%2Fmnras%2F179.3.433). *Monthly Notices of the Royal Astronomical Society*. **179** (3): 433. [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[1977MNRAS.179..433B](https:\/\/ui.adsabs.harvard.edu\/abs\/1977MNRAS.179..433B). 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[\"Universal interferometric signatures of a black hole's photon ring\"](https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7080443). *[Science Advances](https:\/\/en.wikipedia.org\/wiki\/Science_Advances \"Science Advances\")*. **6** (12, eaaz1310) eaaz1310. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[1907\\.04329](https:\/\/arxiv.org\/abs\/1907.04329). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2020SciA....6.1310J](https:\/\/ui.adsabs.harvard.edu\/abs\/2020SciA....6.1310J). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1126\/sciadv.aaz1310](https:\/\/doi.org\/10.1126%2Fsciadv.aaz1310). [PMC](https:\/\/en.wikipedia.org\/wiki\/PMC_\\(identifier\\) \"PMC (identifier)\") [7080443](https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC7080443). 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Retrieved August 28, 2022.\n46. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-46)**\n    [\"Physicists dispute a claim of detecting a black hole's 'photon ring'\"](https:\/\/www.sciencenews.org\/article\/disputed-photon-ring-supermassive-black-hole-image-eht). *Science News*. August 31, 2022. Retrieved September 19, 2022.\n47. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-47)**\n    Medeiros, Lia; Psaltis, Dimitrios; Lauer, Tod R.; Özel, Feryal (April 1, 2023). [\"The Image of the M87 Black Hole Reconstructed with PRIMO\"](https:\/\/doi.org\/10.3847%2F2041-8213%2Facc32d). *The Astrophysical Journal Letters*. **947** (1): L7. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[2304\\.06079](https:\/\/arxiv.org\/abs\/2304.06079). 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[Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2020A\\&A...640A..69K](https:\/\/ui.adsabs.harvard.edu\/abs\/2020A&A...640A..69K). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1051\/0004-6361\/202037493](https:\/\/doi.org\/10.1051%2F0004-6361%2F202037493). [hdl](https:\/\/en.wikipedia.org\/wiki\/Hdl_\\(identifier\\) \"Hdl (identifier)\"):[10261\/227201](https:\/\/hdl.handle.net\/10261%2F227201).\n49. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-EHT3C279PressRelease_49-0)**\n    [\"Something is Lurking in the Heart of Quasar 3C 279\"](https:\/\/eventhorizontelescope.org\/blog\/something-is-lurking-in-the-heart-of-quasar-3c-279). *Event Horizon Telescope*. Retrieved April 20, 2019.\n50. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-50)**\n    Janssen, Michael; Falcke, Heino; Kadler, Matthias; Ros, Eduardo; Wielgus, Maciek; Akiyama, Kazunori; et al. (July 19, 2021). [\"Event Horizon Telescope observations of the jet launching and collimation in Centaurus A\"](https:\/\/doi.org\/10.1038%2Fs41550-021-01417-w). *Nature Astronomy*. **5** (10): 1017–1028\\. [arXiv](https:\/\/en.wikipedia.org\/wiki\/ArXiv_\\(identifier\\) \"ArXiv (identifier)\"):[2111\\.03356](https:\/\/arxiv.org\/abs\/2111.03356). [Bibcode](https:\/\/en.wikipedia.org\/wiki\/Bibcode_\\(identifier\\) \"Bibcode (identifier)\"):[2021NatAs...5.1017J](https:\/\/ui.adsabs.harvard.edu\/abs\/2021NatAs...5.1017J). [doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.1038\/s41550-021-01417-w](https:\/\/doi.org\/10.1038%2Fs41550-021-01417-w). 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[doi](https:\/\/en.wikipedia.org\/wiki\/Doi_\\(identifier\\) \"Doi (identifier)\"):[10\\.3847\/1538-4357\/ac7a40](https:\/\/doi.org\/10.3847%2F1538-4357%2Fac7a40). [ISSN](https:\/\/en.wikipedia.org\/wiki\/ISSN_\\(identifier\\) \"ISSN (identifier)\") [0004-637X](https:\/\/search.worldcat.org\/issn\/0004-637X). [S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [251274752](https:\/\/api.semanticscholar.org\/CorpusID:251274752).\n56. ^ [***a***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:2_56-0) [***b***](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-:2_56-1)\n    [\"Resolving the core of the J1924-2914 blazar with the Event Horizon Telescope\"](https:\/\/eventhorizontelescope.org\/blog\/resolving-core-j1924-2914-blazar-event-horizon-telescope). *Event Horizon Telescope*. August 6, 2022. 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[S2CID](https:\/\/en.wikipedia.org\/wiki\/S2CID_\\(identifier\\) \"S2CID (identifier)\") [256661718](https:\/\/api.semanticscholar.org\/CorpusID:256661718).\n    \n    [![](https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/e\/e1\/CC_BY_icon.svg\/60px-CC_BY_icon.svg.png)](https:\/\/en.wikipedia.org\/wiki\/File:CC_BY_icon.svg) Material was copied from this source, which is available under a [Creative Commons Attribution 4.0](https:\/\/creativecommons.org\/licenses\/by\/3.0\/).\n58. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-58)** [Event Horizon Telescopoe, Organisation](http:\/\/eventhorizontelescope.org\/organization), EHT Website, accessed: 2022-01-30.\n59. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-59)**\n    [\"Funding Support\"](https:\/\/eventhorizontelescope.org\/funding-support). *eventhorizontelescope.org*. Retrieved September 27, 2023.\n60. **[^](https:\/\/en.wikipedia.org\/wiki\/Event_Horizon_Telescope#cite_ref-60)**\n    [\"Industry Donors\"](https:\/\/eventhorizontelescope.org\/industry-donors). *eventhorizontelescope.org*. Retrieved September 27, 2023.\n\n- [Official website](https:\/\/eventhorizontelescope.org\/) [![Edit this at Wikidata](https:\/\/upload.wikimedia.org\/wikipedia\/en\/thumb\/8\/8a\/OOjs_UI_icon_edit-ltr-progressive.svg\/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https:\/\/www.wikidata.org\/wiki\/Q3944788#P856 \"Edit this at Wikidata\")\n- [EHT \"Ask Me Anything\" (AMA) serie](https:\/\/www.reddit.com\/r\/askscience\/comments\/olel36\/askscience_ama_series_were_event_horizon_horizon\/) on [reddit](https:\/\/en.wikipedia.org\/wiki\/Reddit \"Reddit\")\n- [The Next Generation Event Horizon Telescope](https:\/\/www.ngeht.org\/)","meta_canonical":null}

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Boilerpipe Text	From Wikipedia, the free encyclopedia Event Horizon Telescope Alternative names EHT Established 2009 ; 17 years ago Website eventhorizontelescope .org Telescopes Atacama Large Millimeter Array Atacama Pathfinder Experiment Greenland Telescope Heinrich Hertz Submillimeter Telescope IRAM 30m telescope James Clerk Maxwell Telescope Large Millimeter Telescope South Pole Telescope Submillimeter Array Related media on Commons [ edit on Wikidata ] The Event Horizon Telescope ( EHT ) is a telescope array consisting of a global network of radio telescopes . The EHT project combines data from several very-long-baseline interferometry (VLBI) stations around Earth, which form a combined array with an angular resolution sufficient to observe objects the size of a supermassive black hole 's event horizon . The project's observational targets include the two black holes with the largest angular diameter as observed from Earth: the black hole at the center of the supergiant elliptical galaxy Messier 87 , and Sagittarius A* , at the center of the Milky Way . [ 1 ] [ 2 ] The Event Horizon Telescope project is an international collaboration that was launched in 2009 [ 1 ] after a long period of theoretical and technical developments. On the theory side, work on the photon orbit [ 3 ] and first simulations of what a black hole would look like [ 4 ] progressed to predictions of VLBI imaging for the Galactic Center black hole, Sgr A. [ 5 ] [ 6 ] Technical advances in radio observing moved from the first detection of Sgr A, [ 7 ] through VLBI at progressively shorter wavelengths, ultimately leading to detection of horizon scale structure in both Sgr A* and M87. [ 8 ] [ 9 ] The collaboration now comprises over 300 [ 10 ] members, and 60 institutions, working in over 20 countries and regions. [ 11 ] The first image of a black hole, at the center of galaxy Messier 87, was published by the EHT Collaboration on April 10, 2019, in a series of six scientific publications. [ 12 ] The array made this observation at a wavelength of 1.3 mm and with a theoretical diffraction-limited resolution of 25 microarcseconds . In March 2021, the Collaboration presented, for the first time, a polarized-based image of the black hole which may help better reveal the forces giving rise to quasars . [ 13 ] Future plans involve improving the array's resolution by adding new telescopes and by taking shorter-wavelength observations. [ 2 ] [ 14 ] On 12 May 2022, astronomers unveiled the first image of the supermassive black hole at the center of the Milky Way , Sagittarius A* . [ 15 ] Since 2018 the EHT has been capable of imaging at a wavelength of 870 μm (345 GHz), giving an angular resolution of 19 μas, the best resolution of any ground-based telescope. [ 16 ] A schematic diagram of the VLBI mechanism of EHT. Each antenna, spread out over vast distances, has an extremely precise atomic clock . Analogue signals collected by the antenna are converted to digital signals and stored on hard drives together with the time signals provided by the atomic clock. The hard drives are then shipped to a central location to be synchronized. An astronomical observation image is obtained by processing the data gathered from multiple locations. EHT observations during its 2017 M87 multiwavelength campaign decomposed by instrument from lower (EHT/ALMA/SMA) to higher (VERITAS) frequency. (Fermi-LAT in continuous survey mode) (dates also in Modified Julian days ) Soft X-ray image of Sagittarius A* (center) and two light echoes from a recent explosion (circled) The EHT is composed of many radio observatories or radio-telescope facilities around the world, working together to produce a high-sensitivity, high-angular-resolution telescope. Through the technique of very-long-baseline interferometry (VLBI), many independent radio antennas separated by hundreds or thousands of kilometres can act as a phased array , a virtual telescope which can be pointed electronically, with an effective aperture which is the diameter of the entire planet, substantially improving its angular resolution. [ 17 ] The effort includes development and deployment of submillimeter dual polarization receivers, highly stable frequency standards to enable very-long-baseline interferometry at 230–450 GHz, higher-bandwidth VLBI backends and recorders, as well as commissioning of new submillimeter VLBI sites. [ 18 ] Each year since its first data capture in 2006, the EHT array has moved to add more observatories to its global network of radio telescopes. The first image of the Milky Way's supermassive black hole, Sagittarius A, was expected to be produced from data taken in April 2017, [ 19 ] [ 20 ] but because there are no flights in or out of the South Pole during austral winter (April to October), the full data set could not be processed until December 2017, when the shipment of data from the South Pole Telescope arrived. [ 21 ] Data collected on hard drives are transported by commercial freight airplanes [ 22 ] (a so-called sneakernet ) from the various telescopes to the MIT Haystack Observatory and the Max Planck Institute for Radio Astronomy , where the data are cross-correlated and analyzed on a grid computer made from about 800 CPUs all connected through a 40 Gbit/s network. [ 23 ] Because of the COVID-19 pandemic , weather patterns, and celestial mechanics, the 2020 observational campaign was postponed to March 2021. [ 24 ] A series of images descriptive of the level of magnification achieved by the EHT (akin to seeing, from the Earth's surface, an object the size of a tennis ball on the Moon); starts at top-left image and moves counter−clockwise to finish at top-right corner Image of M87 generated from data gathered by the Event Horizon Telescope [ 25 ] [ 26 ] A view of M87* black hole in polarised light The Event Horizon Telescope Collaboration announced its first results in six simultaneous press conferences worldwide on April 10, 2019. [ 25 ] [ 26 ] [ 27 ] The announcement featured the first direct image of a black hole, which showed the supermassive black hole at the center of Messier 87 , designated M87. [ 2 ] [ 28 ] [ 29 ] The scientific results were presented in a series of six papers published in The Astrophysical Journal Letters . [ 30 ] A clockwise rotating black hole was observed in the 6σ region. [ 31 ] The image provided a test for Albert Einstein 's general theory of relativity under extreme conditions. [ 17 ] [ 20 ] Studies have previously tested general relativity by looking at the motions of stars and gas clouds near the edge of a black hole. However, an image of a black hole brings observations even closer to the event horizon. [ 32 ] Relativity predicts a dark shadow-like region, caused by gravitational bending and capture of light, [ 5 ] [ 6 ] which matches the observed image. The published paper states: "Overall, the observed image is consistent with expectations for the shadow of a spinning Kerr black hole as predicted by general relativity." [ 33 ] Paul T. P. Ho, EHT Board member, said: "Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter, and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well." [ 30 ] The image also provided new measurements for the mass and diameter of M87. EHT measured the black hole's mass to be 6.5 ± 0.7 billion solar masses and measured the diameter of its event horizon to be approximately 40 billion kilometres (270 AU; 0.0013 pc; 0.0042 ly), roughly 2.5 times smaller than the shadow that it casts, seen at the center of the image. [ 30 ] [ 32 ] Previous observations of M87 showed that the large-scale jet is inclined at an angle of 17° relative to the observer's line of sight and oriented on the plane of the sky at a position angle of −72°. [ 2 ] [ 34 ] From the enhanced brightness of the southern part of the ring due to relativistic beaming of approaching funnel wall jet emission, EHT concluded the black hole, which anchors the jet, spins clockwise, as seen from Earth. [ 2 ] [ 14 ] EHT simulations allow for both prograde and retrograde inner disk rotation with respect to the black hole, while excluding zero black hole spin using a conservative minimum jet power of 10 42 erg/s via the Blandford–Znajek process . [ 2 ] [ 35 ] Producing an image from data from an array of radio telescopes requires much mathematical work. Four independent teams created images to assess the reliability of the results. [ 36 ] These methods included both an established algorithm in radio astronomy for image reconstruction known as CLEAN , invented by Jan Högbom , [ 37 ] as well as self-calibrating image processing methods [ 38 ] for astronomy such as the CHIRP algorithm created by Katherine Bouman and others. [ 36 ] [ 39 ] The algorithms that were ultimately used were a regularized maximum likelihood (RML) [ 40 ] algorithm and the CLEAN algorithm. [ 36 ] In March 2020, astronomers proposed an improved way of seeing more of the rings in the first black hole image. [ 41 ] [ 42 ] In March 2021, a new photo was revealed, showing how the M87 black hole looks in polarised light. This is the first time astronomers have been able to measure polarisation so close to the edge of a black hole. The lines on the photo mark the orientation of polarisation, which is related to the magnetic field around the shadow of the black hole. [ 43 ] In August 2022, a team led by University of Waterloo researcher Avery Broderick released a "remaster[ed]" version of original image generated from the data collected by the EHT. This image "resolve[d] a fundamental signature of gravity around a black hole", with it showing a displaying photon ring around M87* . [ 44 ] [ 45 ] The claim has been subsequently disputed. [ 46 ] In 2023, EHT released new, sharper images of the M87 black hole, reconstructed from the same 2017 data but created using the PRIMO algorithm. [ 47 ] EHT image of the archetypal blazar 3C 279 showing a relativistic jet down to the AGN core surrounding the supermassive black hole. In April 2020, the EHT released the first 20 microarcsecond resolution images of the archetypal blazar 3C 279 it observed in April 2017. [ 48 ] These images, generated from observations over 4 nights in April 2017, reveal bright components of a jet whose projection on the observer plane exhibit apparent superluminal motions with speeds up to 20 c . [ 49 ] Such apparent superluminal motion from relativistic emitters such as an approaching jet is explained by emission originating closer to the observer (downstream along the jet) catching up with emission originating further from the observer (at the jet base) as the jet propagates close to the speed of light at small angles to the line of sight. Image of Centaurus A showing its black hole jet at different scales In July 2021, high resolution images of the jet produced by a supermassive black hole sitting at the center of Centaurus A were released. With a mass around 5.5 × 10 7 M ☉ , the black hole is not large enough for its photon sphere to be observed, as in EHT images of Messier M87, but its jet extends even beyond its host galaxy while staying as a highly collimated beam which is a point of study. Edge-brightening of the jet was also observed which would exclude models of particle acceleration that are unable to reproduce this effect. The image was 16 times sharper than previous observations and utilized a 1.3 mm wavelength. [ 50 ] [ 51 ] [ 52 ] Sagittarius A in polarised light, image released in 2024 On May 12, 2022, the EHT Collaboration revealed an image of Sagittarius A* , the supermassive black hole at the center of the Milky Way galaxy . The black hole is 27,000 light-years away from Earth; it is thousands of times smaller than M87. Sera Markoff , Co-Chair of the EHT Science Council, said: "We have two completely different types of galaxies and two very different black hole masses, but close to the edge of these black holes they look amazingly similar. This tells us that General Relativity governs these objects up close, and any differences we see further away must be due to differences in the material that surrounds the black holes." [ 53 ] On March 22, 2024, the EHT Collaboration released an image of Sagittarius A in polarized light. [ 54 ] A multifrequency view of the bent jet in Blazar J1924-2914. [ 55 ] [ 56 ] In August 2022, the EHT together with Global Millimeter VLBI Array and the Very Long Baseline Array imaged the distant blazar J1924-2914. They operated at 230 GHz, 86 GHz and 2.3+8.7 GHz, respectively, the highest angular resolution images of polarized emission from a quasar ever obtained. Observations reveal a helically bent jet and the polarization of its emission suggest a toroidal magnetic field structure. The object is used as calibrator for Sagittarius A* sharing strong optical variability and polarization with it. [ 55 ] [ 56 ] NRAO 530 by EHT. The total intensity is shown in grayscale with black contours indicating 10%, 25%, 50%, and 75% of the peak LP intensity. Black dotted contours indicate 25%, 50%, and 75% of the peak polarized intensity. Schematic of the total-intensity and LP components in the EHT fiducial image of NRAO 530; white contours show the total intensity levels; color scale and cyan contours represent the polarized intensity of the method-averaged image. In February 2023, the EHT reported on the observations of the quasar NRAO 530. NRAO 530 (1730−130, J1733−1304) is a flat-spectrum radio quasar (FSRQ) that belongs to the class of bright γ-ray blazars and shows significant variability across the entire electromagnetic spectrum. The source was monitored by the University of Michigan Radio Observatory at 4.8, 8.4, and 14.5 GHz for several decades until 2012. The quasar underwent a dramatic radio outburst in 1997, during which its flux density at 14.5 GHz exceeded 10 Jy, while the average value is ~2 Jy. Since 2002, NRAO 530 has been monitored by the Submillimeter Array (SMA; Maunakea, Hawaii) at 1.3 mm and 870 μm. NRAO 530 has a redshift of z = 0.902 (Junkkarinen 1984), for which 100 μas corresponds to a linear distance of 6 billion pc. The source contains a supermassive black hole, the mass of which is currently uncertain, with estimates ranging from 3 × 10 8 M ☉ to 2 × 10 9 M ☉ . [ 57 ] It was observed with the Event Horizon Telescope on April 5−7, 2017, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A. The observations were performed with the full EHT 2017 array of eight telescopes located at six geographical sites. At z = 0.902, this is the most distant object imaged by the EHT so far. The team reconstructed the first images of the source at 230 GHz, at an angular resolution of about 20 μas, both in total intensity and in linear polarization (LP). Source variability was not detected, that allowed to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which was associated with the core. The feature is linearly polarized, with a fractional polarization of about 5%–8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle about −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field. [ 57 ] Collaborating institutes [ edit ] The EHT Collaboration consists of 13 stakeholder institutes: [ 58 ] the Academia Sinica Institute of Astronomy and Astrophysics the University of Arizona the University of Chicago the East Asian Observatory Goethe University Frankfurt Smithsonian Astrophysical Observatory (part of the Harvard–Smithsonian Center for Astrophysics ) Institut de radioastronomie millimétrique (IRAM, itself a collaboration between the French CNRS , the German Max Planck Society , and the Spanish Instituto Geográfico Nacional ) Large Millimeter Telescope Alfonso Serrano Max Planck Institute for Radio Astronomy MIT Haystack Observatory National Astronomical Observatory of Japan Perimeter Institute for Theoretical Physics Radboud University Locations of the telescopes that make up the EHT array. A global map showing the radio observatories that form the Event Horizon Telescope (EHT) network used to image the Milky Way's central black hole, Sagittarius A. The telescopes highlighted in yellow were part of the EHT network during the observations of Sagittarius A* in 2017. These include the Atacama Large Millimeter/submillimeter Array (ALMA), the Atacama Pathfinder EXperiment (APEX), IRAM 30-meter telescope (30-M), James Clark Maxwell Telescope (JCMT), Large Millimeter Telescope (LMT), Submillimeter Array (SMA), Submillimetere Telescope (SMT) and South Pole Telescope (SPT). Highlighted in blue are the three telescopes added to the EHT Collaboration after 2018: the Greenland Telescope (GLT), the NOrthern Extended Millimeter Array (NOEMA) in France, and the University of Arizona ARO 12-meter Telescope at Kitt Peak. The EHT Collaboration receives funding from numerous sources including: [ 59 ] United States National Science Foundation European Research Council National Science and Technology Council of Taiwan (formerly Ministry of Science and Technology of Taiwan) Max Planck Society Consejo Nacional de Ciencia y Technologia, Mexico John Templeton Foundation Gordon and Betty Moore Foundation Japan Society for the Promotion of Science Natural Sciences and Engineering Research Council of Canada Academia Sinica Smithsonian Institution Additionally, Western Digital and Xilinx are industry donors. [ 60 ] ^ a b Doeleman, Sheperd (June 21, 2009). "Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole". Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers . 2010 : 68. arXiv : 0906.3899 . Bibcode : 2009astro2010S..68D . ^ a b c d e f The Event Horizon Telescope Collaboration (April 10, 2019). "First M87 Event Horizon Telescope Results. I. 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Nature Astronomy . 5 (10): 982– 983. Bibcode : 2021NatAs...5..982G . doi : 10.1038/s41550-021-01420-1 . ISSN 2397-3366 . S2CID 237675257 . ^ "EHT Pinpoints Dark Heart of the Nearest Radio Galaxy" . Event Horizon Telescope. July 19, 2021 . Retrieved July 20, 2021 . ^ "Astronomers reveal first image of the black hole at the heart of our galaxy" (Press release). ESO. May 12, 2022. ^ "Astronomers unveil strong magnetic fields spiraling at the edge of Milky Way's central black hole" . ESO . Retrieved March 27, 2024 . ^ a b Issaoun, Sara; Wielgus, Maciek; Jorstad, Svetlana; Krichbaum, Thomas P.; Blackburn, Lindy; Janssen, Michael; Chan, Chi-kwan; Pesce, Dominic W.; Gómez, José L.; Akiyama, Kazunori; Mościbrodzka, Monika; Martí-Vidal, Iván; Chael, Andrew; Lico, Rocco; Liu, Jun (August 1, 2022). "Resolving the Inner Parsec of the Blazar J1924–2914 with the Event Horizon Telescope" . The Astrophysical Journal . 934 (2): 145. arXiv : 2208.01662 . Bibcode : 2022ApJ...934..145I . doi : 10.3847/1538-4357/ac7a40 . ISSN 0004-637X . S2CID 251274752 . ^ a b "Resolving the core of the J1924-2914 blazar with the Event Horizon Telescope" . Event Horizon Telescope . August 6, 2022 . Retrieved August 14, 2022 . ^ a b Jorstad, Svetlana; et al. (February 1, 2023). "The Event Horizon Telescope Image of the Quasar NRAO 530" . The Astrophysical Journal . 943 (2): 170. arXiv : 2302.04622 . Bibcode : 2023ApJ...943..170J . doi : 10.3847/1538-4357/acaea8 . S2CID 256661718 . Material was copied from this source, which is available under a Creative Commons Attribution 4.0 . ^ Event Horizon Telescopoe, Organisation , EHT Website, accessed: 2022-01-30. ^ "Funding Support" . eventhorizontelescope.org . Retrieved September 27, 2023 . ^ "Industry Donors" . eventhorizontelescope.org . Retrieved September 27, 2023 . Official website EHT "Ask Me Anything" (AMA) serie on reddit The Next Generation Event Horizon Telescope
Markdown	[Jump to content](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#bodyContent) Main menu Main menu move to sidebar hide Navigation - [Main page](https://en.wikipedia.org/wiki/Main_Page "Visit the main page [z]") - [Contents](https://en.wikipedia.org/wiki/Wikipedia:Contents "Guides to browsing Wikipedia") - [Current events](https://en.wikipedia.org/wiki/Portal:Current_events "Articles related to current events") - [Random article](https://en.wikipedia.org/wiki/Special:Random "Visit a randomly selected article [x]") - [About Wikipedia](https://en.wikipedia.org/wiki/Wikipedia:About "Learn about Wikipedia and how it works") - [Contact us](https://en.wikipedia.org/wiki/Wikipedia:Contact_us "How to contact Wikipedia") Contribute - [Help](https://en.wikipedia.org/wiki/Help:Contents "Guidance on how to use and edit Wikipedia") - [Learn to edit](https://en.wikipedia.org/wiki/Help:Introduction "Learn how to edit Wikipedia") - [Community portal](https://en.wikipedia.org/wiki/Wikipedia:Community_portal "The hub for editors") - [Recent changes](https://en.wikipedia.org/wiki/Special:RecentChanges "A list of recent changes to Wikipedia [r]") - [Upload file](https://en.wikipedia.org/wiki/Wikipedia:File_upload_wizard "Add images or other media for use on Wikipedia") - [Special pages](https://en.wikipedia.org/wiki/Special:SpecialPages "A list of all special pages [q]") [![](https://en.wikipedia.org/static/images/icons/enwiki-25.svg) ![Wikipedia](https://en.wikipedia.org/static/images/mobile/copyright/wikipedia-wordmark-en-25.svg) ![The Free Encyclopedia](https://en.wikipedia.org/static/images/mobile/copyright/wikipedia-tagline-en-25.svg)](https://en.wikipedia.org/wiki/Main_Page) [Search](https://en.wikipedia.org/wiki/Special:Search "Search Wikipedia [f]") Appearance - [Donate](https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en) - [Create account](https://en.wikipedia.org/w/index.php?title=Special:CreateAccount&returnto=Event+Horizon+Telescope "You are encouraged to create an account and log in; however, it is not mandatory") - [Log in](https://en.wikipedia.org/w/index.php?title=Special:UserLogin&returnto=Event+Horizon+Telescope "You're encouraged to log in; however, it's not mandatory. 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[o]") ## Contents move to sidebar hide - [(Top)](https://en.wikipedia.org/wiki/Event_Horizon_Telescope) - [1 Telescope array](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#Telescope_array) - [2 Published images](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#Published_images) Toggle Published images subsection - [2\.1 Messier 87\](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#Messier_87) - [2\.2 3C 279](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#3C_279) - [2\.3 Centaurus A](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#Centaurus_A) - [2\.4 Sagittarius A\](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#Sagittarius_A) - [2\.5 J1924-2914](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#J1924-2914) - [2\.6 NRAO 530](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#NRAO_530) - [3 Collaborating institutes](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#Collaborating_institutes) - [4 Funding](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#Funding) - [5 References](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#References) - [6 External links](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#External_links) Toggle the table of contents # Event Horizon Telescope 39 languages - [العربية](https://ar.wikipedia.org/wiki/%D9%85%D9%82%D8%B1%D8%A7%D8%A8_%D8%A3%D9%81%D9%82_%D8%A7%D9%84%D8%AD%D8%AF%D8%AB "مقراب أفق الحدث – Arabic") - [অসমীয়া](https://as.wikipedia.org/wiki/%E0%A6%87%E0%A6%AD%E0%A7%87%E0%A6%A3%E0%A7%8D%E0%A6%9F_%E0%A6%B9%27%E0%A7%B0%E0%A6%BE%E0%A6%87%E0%A6%9C%27%E0%A6%A8_%E0%A6%9F%E0%A7%87%E0%A6%B2%E0%A6%BF%E0%A6%B8%E0%A7%8D%E0%A6%95%27%E0%A6%AA "ইভেণ্ট হ'ৰাইজ'ন টেলিস্ক'প – Assamese") - [Azərbaycanca](https://az.wikipedia.org/wiki/Hadis%C9%99_%C3%9Cf%C3%BCq%C3%BC_Teleskopu "Hadisə Üfüqü Teleskopu – Azerbaijani") - [বাংলা](https://bn.wikipedia.org/wiki/%E0%A6%87%E0%A6%AD%E0%A7%87%E0%A6%A8%E0%A7%8D%E0%A6%9F_%E0%A6%B9%E0%A6%B0%E0%A6%BE%E0%A6%87%E0%A6%9C%E0%A6%A8_%E0%A6%9F%E0%A7%87%E0%A6%B2%E0%A6%BF%E0%A6%B8%E0%A7%8D%E0%A6%95%E0%A7%8B%E0%A6%AA "ইভেন্ট হরাইজন টেলিস্কোপ – Bangla") - [Català](https://ca.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Catalan") - [Čeština](https://cs.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Czech") - [Cymraeg](https://cy.wikipedia.org/wiki/Telesgop_Event_Horizon "Telesgop Event Horizon – Welsh") - [Dansk](https://da.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Danish") - [Deutsch](https://de.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – German") - [Ελληνικά](https://el.wikipedia.org/wiki/%CE%A4%CE%B7%CE%BB%CE%B5%CF%83%CE%BA%CF%8C%CF%80%CE%B9%CE%BF_%CE%9F%CF%81%CE%AF%CE%B6%CE%BF%CE%BD%CF%84%CE%B1_%CE%93%CE%B5%CE%B3%CE%BF%CE%BD%CF%8C%CF%84%CF%89%CE%BD "Τηλεσκόπιο Ορίζοντα Γεγονότων – Greek") - [Español](https://es.wikipedia.org/wiki/Telescopio_del_Horizonte_de_Sucesos "Telescopio del Horizonte de Sucesos – Spanish") - [Euskara](https://eu.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Basque") - [فارسی](https://fa.wikipedia.org/wiki/%D8%AA%D9%84%D8%B3%DA%A9%D9%88%D9%BE_%D8%A7%D9%81%D9%82_%D8%B1%D9%88%DB%8C%D8%AF%D8%A7%D8%AF "تلسکوپ افق رویداد – Persian") - [Suomi](https://fi.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Finnish") - [Français](https://fr.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – French") - [Galego](https://gl.wikipedia.org/wiki/Telescopio_de_Horizonte_de_Eventos "Telescopio de Horizonte de Eventos – Galician") - [Magyar](https://hu.wikipedia.org/wiki/Esem%C3%A9nyhorizont_T%C3%A1vcs%C5%91 "Eseményhorizont Távcső – Hungarian") - [Bahasa Indonesia](https://id.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Indonesian") - [Italiano](https://it.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Italian") - [日本語](https://ja.wikipedia.org/wiki/%E3%82%A4%E3%83%99%E3%83%B3%E3%83%88%E3%83%9B%E3%83%A9%E3%82%A4%E3%82%BA%E3%83%B3%E3%83%86%E3%83%AC%E3%82%B9%E3%82%B3%E3%83%BC%E3%83%97 "イベントホライズンテレスコープ – Japanese") - [한국어](https://ko.wikipedia.org/wiki/%EC%82%AC%EC%83%81%EC%88%98%ED%8F%89%EC%84%A0%EB%A7%9D%EC%9B%90%EA%B2%BD "사상수평선망원경 – Korean") - [Lietuvių](https://lt.wikipedia.org/wiki/%C4%AEvyki%C5%B3_horizonto_teleskopas "Įvykių horizonto teleskopas – Lithuanian") - [Bahasa Melayu](https://ms.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Malay") - [Nederlands](https://nl.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Dutch") - [Polski](https://pl.wikipedia.org/wiki/Teleskop_Horyzontu_Zdarze%C5%84 "Teleskop Horyzontu Zdarzeń – Polish") - [Português](https://pt.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Portuguese") - [Română](https://ro.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Romanian") - [Русский](https://ru.wikipedia.org/wiki/%D0%A2%D0%B5%D0%BB%D0%B5%D1%81%D0%BA%D0%BE%D0%BF_%D0%B3%D0%BE%D1%80%D0%B8%D0%B7%D0%BE%D0%BD%D1%82%D0%B0_%D1%81%D0%BE%D0%B1%D1%8B%D1%82%D0%B8%D0%B9 "Телескоп горизонта событий – Russian") - [Slovenčina](https://sk.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Slovak") - [Српски / srpski](https://sr.wikipedia.org/wiki/%D0%A2%D0%B5%D0%BB%D0%B5%D1%81%D0%BA%D0%BE%D0%BF_%D1%85%D0%BE%D1%80%D0%B8%D0%B7%D0%BE%D0%BD%D1%82%D0%B0_%D0%B4%D0%BE%D0%B3%D0%B0%D1%92%D0%B0%D1%98%D0%B0 "Телескоп хоризонта догађаја – Serbian") - [Svenska](https://sv.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Swedish") - [ไทย](https://th.wikipedia.org/wiki/%E0%B8%81%E0%B8%A5%E0%B9%89%E0%B8%AD%E0%B8%87%E0%B9%82%E0%B8%97%E0%B8%A3%E0%B8%97%E0%B8%A3%E0%B8%A3%E0%B8%A8%E0%B8%99%E0%B9%8C%E0%B8%82%E0%B8%AD%E0%B8%9A%E0%B8%9F%E0%B9%89%E0%B8%B2%E0%B9%80%E0%B8%AB%E0%B8%95%E0%B8%B8%E0%B8%81%E0%B8%B2%E0%B8%A3%E0%B8%93%E0%B9%8C "กล้องโทรทรรศน์ขอบฟ้าเหตุการณ์ – Thai") - [Tagalog](https://tl.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Tagalog") - [Türkçe](https://tr.wikipedia.org/wiki/Olay_Ufku_Teleskobu "Olay Ufku Teleskobu – Turkish") - [Українська](https://uk.wikipedia.org/wiki/%D0%A2%D0%B5%D0%BB%D0%B5%D1%81%D0%BA%D0%BE%D0%BF_%D0%B3%D0%BE%D1%80%D0%B8%D0%B7%D0%BE%D0%BD%D1%82%D1%83_%D0%BF%D0%BE%D0%B4%D1%96%D0%B9 "Телескоп горизонту подій – Ukrainian") - [اردو](https://ur.wikipedia.org/wiki/%D8%A7%DB%8C%D9%88%D9%86%D9%B9_%DB%81%D9%88%D8%B1%D8%A7%D8%A6%D8%B2%D9%86_%D9%B9%DB%8C%D9%84%DB%8C_%D8%B3%DA%A9%D9%88%D9%BE "ایونٹ ہورائزن ٹیلی سکوپ – Urdu") - [Tiếng Việt](https://vi.wikipedia.org/wiki/K%C3%ADnh_thi%C3%AAn_v%C4%83n_Ch%C3%A2n_tr%E1%BB%9Di_s%E1%BB%B1_ki%E1%BB%87n "Kính thiên văn Chân trời sự kiện – Vietnamese") - [閩南語 / Bân-lâm-gí](https://zh-min-nan.wikipedia.org/wiki/Event_Horizon_Telescope "Event Horizon Telescope – Minnan") - [中文](https://zh.wikipedia.org/wiki/%E4%BA%8B%E4%BB%B6%E8%A6%96%E7%95%8C%E6%9C%9B%E9%81%A0%E9%8F%A1 "事件視界望遠鏡 – Chinese") [Edit links](https://www.wikidata.org/wiki/Special:EntityPage/Q3944788#sitelinks-wikipedia "Edit interlanguage links") - [Article](https://en.wikipedia.org/wiki/Event_Horizon_Telescope "View the content page [c]") - [Talk](https://en.wikipedia.org/wiki/Talk:Event_Horizon_Telescope "Discuss improvements to the content page [t]") English - [Read](https://en.wikipedia.org/wiki/Event_Horizon_Telescope) - [Edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit "Edit this page [e]") - [View history](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=history "Past revisions of this page [h]") Tools Tools move to sidebar hide Actions - 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[Get shortened URL](https://en.wikipedia.org/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FEvent_Horizon_Telescope) Print/export - [Download as PDF](https://en.wikipedia.org/w/index.php?title=Special:DownloadAsPdf&page=Event_Horizon_Telescope&action=show-download-screen "Download this page as a PDF file") - [Printable version](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&printable=yes "Printable version of this page [p]") In other projects - [Wikimedia Commons](https://commons.wikimedia.org/wiki/Category:Event_Horizon_Telescope) - [Wikidata item](https://www.wikidata.org/wiki/Special:EntityPage/Q3944788 "Structured data on this page hosted by Wikidata [g]") Appearance move to sidebar hide From Wikipedia, the free encyclopedia Global radio telescope array Observatory \| \| \| \|---\|---\| \| [![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/35/Event_Horizon_Telescope.svg/250px-Event_Horizon_Telescope.svg.png)](https://en.wikipedia.org/wiki/File:Event_Horizon_Telescope.svg) \| \| \| Alternative names \| EHT [![Edit this on Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q3944788?uselang=en#P1813 "Edit this on Wikidata") \| \| Established \| 2009; 17 years ago (2009) \| \| Website \| [eventhorizontelescope.org](https://eventhorizontelescope.org/) [![Edit this at Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q3944788#P856 "Edit this at Wikidata") \| \| Telescopes \| [Atacama Large Millimeter Array](https://en.wikipedia.org/wiki/Atacama_Large_Millimeter_Array "Atacama Large Millimeter Array") [Atacama Pathfinder Experiment](https://en.wikipedia.org/wiki/Atacama_Pathfinder_Experiment "Atacama Pathfinder Experiment") [Greenland Telescope](https://en.wikipedia.org/wiki/Greenland_Telescope "Greenland Telescope") [Heinrich Hertz Submillimeter Telescope](https://en.wikipedia.org/wiki/Heinrich_Hertz_Submillimeter_Telescope "Heinrich Hertz Submillimeter Telescope") [IRAM 30m telescope](https://en.wikipedia.org/wiki/IRAM_30m_telescope "IRAM 30m telescope") [James Clerk Maxwell Telescope](https://en.wikipedia.org/wiki/James_Clerk_Maxwell_Telescope "James Clerk Maxwell Telescope") [Large Millimeter Telescope](https://en.wikipedia.org/wiki/Large_Millimeter_Telescope "Large Millimeter Telescope") [South Pole Telescope](https://en.wikipedia.org/wiki/South_Pole_Telescope "South Pole Telescope") [Submillimeter Array](https://en.wikipedia.org/wiki/Submillimeter_Array "Submillimeter Array") [![Edit this on Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q3944788?uselang=en#P527 "Edit this on Wikidata") \| \| [![](https://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/20px-Commons-logo.svg.png)](https://en.wikipedia.org/wiki/File:Commons-logo.svg) [Related media on Commons](https://commons.wikimedia.org/wiki/Category:Event_Horizon_Telescope "commons:Category:Event Horizon Telescope") \| \| \| \[[edit on Wikidata](https://www.wikidata.org/wiki/Q3944788 "d:Q3944788")\] \| \| The Event Horizon Telescope (EHT) is a [telescope array](https://en.wikipedia.org/wiki/Astronomical_interferometer "Astronomical interferometer") consisting of a global network of [radio telescopes](https://en.wikipedia.org/wiki/Radio_telescope "Radio telescope"). The EHT project combines data from several [very-long-baseline interferometry](https://en.wikipedia.org/wiki/Very-long-baseline_interferometry "Very-long-baseline interferometry") (VLBI) stations around Earth, which form a combined array with an [angular resolution](https://en.wikipedia.org/wiki/Angular_resolution "Angular resolution") sufficient to observe objects the size of a [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole")'s [event horizon](https://en.wikipedia.org/wiki/Event_horizon "Event horizon"). The project's observational targets include the two [black holes](https://en.wikipedia.org/wiki/Black_hole "Black hole") with the largest [angular diameter](https://en.wikipedia.org/wiki/Angular_diameter "Angular diameter") as observed from Earth: the black hole at the center of the [supergiant](https://en.wikipedia.org/wiki/Type-cD_galaxy "Type-cD galaxy") [elliptical galaxy](https://en.wikipedia.org/wiki/Elliptical_galaxy "Elliptical galaxy") [Messier 87](https://en.wikipedia.org/wiki/Messier_87 "Messier 87"), and [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A"), at [the center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way").[\[1\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-wp-2009-1)[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2) The Event Horizon Telescope project is an international collaboration that was launched in 2009[\[1\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-wp-2009-1) after a long period of theoretical and technical developments. On the theory side, work on the photon orbit[\[3\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-3) and first simulations of what a black hole would look like[\[4\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-4) progressed to predictions of VLBI imaging for the Galactic Center black hole, Sgr A\.[\[5\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:0-5)[\[6\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:0a-6) Technical advances in radio observing moved from the first detection of Sgr A\,[\[7\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-7) through VLBI at progressively shorter wavelengths, ultimately leading to detection of horizon scale structure in both Sgr A\ and M87.[\[8\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-Sheperd2008-8)[\[9\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-Sheperd2012-9) The collaboration now comprises over 300[\[10\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-breakthrough-prize-10) members, and 60 institutions, working in over 20 countries and regions.[\[11\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-website-11) The first image of a black hole, at the center of galaxy Messier 87, was published by the EHT Collaboration on April 10, 2019, in a series of six scientific publications.[\[12\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-apjl-focus-12) The array made this observation at a wavelength of 1.3 mm and with a theoretical [diffraction-limited resolution](https://en.wikipedia.org/wiki/Diffraction-limited_resolution "Diffraction-limited resolution") of 25 [microarcseconds](https://en.wikipedia.org/wiki/Microarcsecond "Microarcsecond"). In March 2021, the Collaboration presented, for the first time, a [polarized-based image](https://en.wikipedia.org/wiki/Polarization_\(waves\) "Polarization (waves)") of the [black hole](https://en.wikipedia.org/wiki/Black_hole "Black hole") which may help better reveal the forces giving rise to [quasars](https://en.wikipedia.org/wiki/Quasar "Quasar").[\[13\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20210324-13) Future plans involve improving the array's resolution by adding new telescopes and by taking shorter-wavelength observations.[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[14\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-aasnova-20190410-14) On 12 May 2022, astronomers unveiled the first image of the supermassive black hole at the center of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way"), [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A").[\[15\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20220512-15) Since 2018 the EHT has been capable of imaging at a wavelength of 870 μm (345 GHz), giving an angular resolution of 19 μas, the best resolution of any ground-based telescope.[\[16\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-16) ## Telescope array \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=1 "Edit section: Telescope array")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/1/13/EHT-infography.png/250px-EHT-infography.png)](https://en.wikipedia.org/wiki/File:EHT-infography.png) A schematic diagram of the VLBI mechanism of EHT. Each antenna, spread out over vast distances, has an extremely precise [atomic clock](https://en.wikipedia.org/wiki/Atomic_clock "Atomic clock"). [Analogue signals](https://en.wikipedia.org/wiki/Analog_signal "Analog signal") collected by the antenna are converted to [digital signals](https://en.wikipedia.org/wiki/Digital_signal "Digital signal") and stored on hard drives together with the time signals provided by the atomic clock. The hard drives are then shipped to a central location to be synchronized. An astronomical observation image is obtained by processing the data gathered from multiple locations. [![](https://upload.wikimedia.org/wikipedia/commons/thumb/2/23/EHTobservations2017.jpg/250px-EHTobservations2017.jpg)](https://en.wikipedia.org/wiki/File:EHTobservations2017.jpg) EHT observations during its 2017 M87 multiwavelength campaign decomposed by instrument from lower (EHT/ALMA/SMA) to higher (VERITAS) frequency. (Fermi-LAT in continuous survey mode) (dates also in [Modified Julian days](https://en.wikipedia.org/wiki/Julian_day#Variants "Julian day")) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Sagittarius_A%2A.jpg/250px-Sagittarius_A%2A.jpg)](https://en.wikipedia.org/wiki/File:Sagittarius_A.jpg) Soft [X-ray](https://en.wikipedia.org/wiki/X-ray "X-ray") image of [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A") (center) and two [light echoes](https://en.wikipedia.org/wiki/Light_echo "Light echo") from a recent explosion (circled) The EHT is composed of many radio observatories or radio-telescope facilities around the world, working together to produce a high-sensitivity, high-angular-resolution telescope. Through the technique of [very-long-baseline interferometry](https://en.wikipedia.org/wiki/Very-long-baseline_interferometry "Very-long-baseline interferometry") (VLBI), many independent radio antennas separated by hundreds or thousands of kilometres can act as a [phased array](https://en.wikipedia.org/wiki/Phased_array "Phased array"), a virtual telescope which can be pointed electronically, with an [effective aperture](https://en.wikipedia.org/wiki/Aperture_synthesis "Aperture synthesis") which is the diameter of the entire planet, substantially improving its angular resolution.[\[17\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-O'Neil2015-17) The effort includes development and deployment of [submillimeter](https://en.wikipedia.org/wiki/Submillimetre_astronomy "Submillimetre astronomy") dual [polarization](https://en.wikipedia.org/wiki/Polarization_\(waves\) "Polarization (waves)") receivers, highly stable frequency standards to enable very-long-baseline interferometry at 230–450 GHz, higher-bandwidth VLBI backends and recorders, as well as commissioning of new submillimeter VLBI sites.[\[18\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-18) Each year since its first data capture in 2006, the EHT array has moved to add more observatories to its global network of radio telescopes. The first image of the Milky Way's supermassive black hole, Sagittarius A\, was expected to be produced from data taken in April 2017,[\[19\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-19)[\[20\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-nature543-20) but because there are no flights in or out of the South Pole during austral winter (April to October), the full data set could not be processed until December 2017, when the shipment of data from the [South Pole Telescope](https://en.wikipedia.org/wiki/South_Pole_Telescope "South Pole Telescope") arrived.[\[21\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-21) Data collected on hard drives are transported by commercial freight airplanes[\[22\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-22) (a so-called [sneakernet](https://en.wikipedia.org/wiki/Sneakernet "Sneakernet")) from the various telescopes to the [MIT](https://en.wikipedia.org/wiki/MIT "MIT") [Haystack Observatory](https://en.wikipedia.org/wiki/Haystack_Observatory "Haystack Observatory") and the [Max Planck Institute for Radio Astronomy](https://en.wikipedia.org/wiki/Max_Planck_Institute_for_Radio_Astronomy "Max Planck Institute for Radio Astronomy"), where the data are [cross-correlated](https://en.wikipedia.org/wiki/Cross-correlation "Cross-correlation") and analyzed on a [grid computer](https://en.wikipedia.org/wiki/Grid_computing "Grid computing") made from about 800 [CPUs](https://en.wikipedia.org/wiki/Central_processing_unit "Central processing unit") all connected through a 40 Gbit/s network.[\[23\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-23) Because of the [COVID-19 pandemic](https://en.wikipedia.org/wiki/COVID-19_pandemic "COVID-19 pandemic"), weather patterns, and celestial mechanics, the 2020 observational campaign was postponed to March 2021.[\[24\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-24) ## Published images \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=2 "Edit section: Published images")\] ### Messier 87\* \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=3 "Edit section: Messier 87")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Event_Horizon_Telescope_and_Apollo_16.png/250px-Event_Horizon_Telescope_and_Apollo_16.png)](https://en.wikipedia.org/wiki/File:Event_Horizon_Telescope_and_Apollo_16.png) A series of images descriptive of the level of magnification achieved by the EHT (akin to seeing, from the Earth's surface, an object the size of a tennis ball on the Moon); starts at top-left image and moves counter−clockwise to finish at top-right corner [![](https://upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Black_hole_-_Messier_87_crop_max_res.jpg/250px-Black_hole_-_Messier_87_crop_max_res.jpg)](https://en.wikipedia.org/wiki/File:Black_hole_-_Messier_87_crop_max_res.jpg) Image of [M87\](https://en.wikipedia.org/wiki/M87* "M87") generated from data gathered by the Event Horizon Telescope[\[25\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20190410-25)[\[26\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NASA-20190410-26) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif/lossy-page1-250px-A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif.jpg)](https://en.wikipedia.org/wiki/File:A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif) A view of [M87\](https://en.wikipedia.org/wiki/M87* "M87") black hole in polarised light The Event Horizon Telescope Collaboration announced its first results in six simultaneous press conferences worldwide on April 10, 2019.[\[25\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20190410-25)[\[26\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NASA-20190410-26)[\[27\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-27) The announcement featured the first direct image of a black hole, which showed the [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole") at the center of [Messier 87](https://en.wikipedia.org/wiki/Messier_87 "Messier 87"), designated M87\.[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[28\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NS-name-28)[\[29\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20190412-29) The scientific results were presented in a series of six papers published in [The Astrophysical Journal Letters](https://en.wikipedia.org/wiki/The_Astrophysical_Journal_Letters "The Astrophysical Journal Letters").[\[30\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eso1907-30) A clockwise [rotating black hole](https://en.wikipedia.org/wiki/Rotating_black_hole "Rotating black hole") was observed in the 6σ region.[\[31\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-RotBlackHole-31) The image provided a test for [Albert Einstein](https://en.wikipedia.org/wiki/Albert_Einstein "Albert Einstein")'s [general theory of relativity](https://en.wikipedia.org/wiki/General_relativity "General relativity") under extreme conditions.[\[17\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-O'Neil2015-17)[\[20\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-nature543-20) Studies have previously tested general relativity by looking at the motions of stars and gas clouds near the edge of a black hole. However, an image of a black hole brings observations even closer to the event horizon.[\[32\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-sciencenews-32) Relativity predicts a dark shadow-like region, caused by gravitational bending and capture of light,[\[5\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:0-5)[\[6\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:0a-6) which matches the observed image. The published paper states: "Overall, the observed image is consistent with expectations for the shadow of a [spinning Kerr black hole](https://en.wikipedia.org/wiki/Spinning_Kerr_black_hole "Spinning Kerr black hole") as predicted by general relativity."[\[33\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-33) Paul T. P. Ho, EHT Board member, said: "Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter, and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well."[\[30\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eso1907-30) The image also provided new measurements for the mass and diameter of M87\. EHT measured the black hole's mass to be 6\.5±0\.7 billion [solar masses](https://en.wikipedia.org/wiki/Solar_masses "Solar masses") and measured the diameter of its event horizon to be approximately 40 billion kilometres (270 AU; 0.0013 pc; 0.0042 ly), roughly 2.5 times smaller than the shadow that it casts, seen at the center of the image.[\[30\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eso1907-30)[\[32\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-sciencenews-32) Previous observations of M87 showed that the large-scale [jet](https://en.wikipedia.org/wiki/Astrophysical_jet "Astrophysical jet") is inclined at an angle of 17° relative to the observer's line of sight and oriented on the plane of the sky at a [position angle](https://en.wikipedia.org/wiki/Position_angle "Position angle") of −72°.[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[34\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-34) From the enhanced brightness of the southern part of the ring due to [relativistic beaming](https://en.wikipedia.org/wiki/Relativistic_beaming "Relativistic beaming") of approaching funnel wall jet emission, EHT concluded the black hole, which anchors the jet, spins clockwise, as seen from Earth.[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[14\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-aasnova-20190410-14) EHT simulations allow for both prograde and retrograde inner disk rotation with respect to the black hole, while excluding zero black hole spin using a conservative minimum jet power of 1042 erg/s via the [Blandford–Znajek process](https://en.wikipedia.org/wiki/Blandford%E2%80%93Znajek_process "Blandford–Znajek process").[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[35\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-35) Producing an image from data from an array of radio telescopes requires much mathematical work. Four independent teams created images to assess the reliability of the results.[\[36\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-imaging-36) These methods included both an established algorithm in [radio astronomy](https://en.wikipedia.org/wiki/Radio_astronomy "Radio astronomy") for [image reconstruction](https://en.wikipedia.org/wiki/Image_reconstruction "Image reconstruction") known as [CLEAN](https://en.wikipedia.org/wiki/CLEAN_\(algorithm\) "CLEAN (algorithm)"), invented by [Jan Högbom](https://en.wikipedia.org/wiki/Jan_H%C3%B6gbom "Jan Högbom"),[\[37\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-H%C3%B6gbom1974-37) as well as self-calibrating [image processing](https://en.wikipedia.org/wiki/Image_processing "Image processing") methods[\[38\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-bnss,etc-38) for astronomy such as the [CHIRP algorithm](https://en.wikipedia.org/wiki/CHIRP_\(algorithm\) "CHIRP (algorithm)") created by [Katherine Bouman](https://en.wikipedia.org/wiki/Katherine_Bouman "Katherine Bouman") and others.[\[36\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-imaging-36)[\[39\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-39) The algorithms that were ultimately used were a [regularized](https://en.wikipedia.org/wiki/Regularization_\(mathematics\) "Regularization (mathematics)") [maximum likelihood](https://en.wikipedia.org/wiki/Maximum_likelihood "Maximum likelihood") (RML)[\[40\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-40) algorithm and the [CLEAN](https://en.wikipedia.org/wiki/CLEAN_\(algorithm\) "CLEAN (algorithm)") algorithm.[\[36\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-imaging-36) In March 2020, astronomers proposed an improved way of seeing more of the rings in the first black hole image.[\[41\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20200328-41)[\[42\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-42) In March 2021, a new photo was revealed, showing how the M87 black hole looks in polarised light. This is the first time astronomers have been able to measure polarisation so close to the edge of a black hole. The lines on the photo mark the orientation of polarisation, which is related to the magnetic field around the shadow of the black hole.[\[43\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-43) In August 2022, a team led by [University of Waterloo](https://en.wikipedia.org/wiki/University_of_Waterloo "University of Waterloo") researcher Avery Broderick released a "remaster\[ed\]" version of original image generated from the data collected by the EHT. This image "resolve\[d\] a fundamental signature of gravity around a black hole", with it showing a displaying [photon ring](https://en.wikipedia.org/wiki/Photon_ring "Photon ring") around [M87\](https://en.wikipedia.org/wiki/M87* "M87").[\[44\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-44)[\[45\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-45) The claim has been subsequently disputed.[\[46\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-46) In 2023, EHT released new, sharper images of the M87 black hole, reconstructed from the same 2017 data but created using the PRIMO algorithm.[\[47\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-47) ### 3C 279 \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=4 "Edit section: 3C 279")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/EHT3C279PressReleaseImage.png/250px-EHT3C279PressReleaseImage.png)](https://en.wikipedia.org/wiki/File:EHT3C279PressReleaseImage.png) EHT image of the archetypal blazar 3C 279 showing a relativistic jet down to the AGN core surrounding the supermassive black hole. In April 2020, the EHT released the first 20 microarcsecond resolution images of the archetypal [blazar](https://en.wikipedia.org/wiki/Blazar "Blazar") [3C 279](https://en.wikipedia.org/wiki/3C_279 "3C 279") it observed in April 2017.[\[48\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-EHT3C279-48) These images, generated from observations over 4 nights in April 2017, reveal bright components of a jet whose projection on the observer plane exhibit apparent [superluminal motions](https://en.wikipedia.org/wiki/Superluminal_motion "Superluminal motion") with speeds up to 20 c.[\[49\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-EHT3C279PressRelease-49) Such apparent superluminal motion from relativistic emitters such as an approaching jet is explained by emission originating closer to the observer (downstream along the jet) catching up with emission originating further from the observer (at the jet base) as the jet propagates close to the speed of light at small angles to the line of sight. ### Centaurus A \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=5 "Edit section: Centaurus A")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/61/EHTcentaurusA2021.jpg/250px-EHTcentaurusA2021.jpg)](https://en.wikipedia.org/wiki/File:EHTcentaurusA2021.jpg) Image of Centaurus A showing its black hole jet at different scales In July 2021, high resolution images of the jet produced by a supermassive black hole sitting at the center of [Centaurus A](https://en.wikipedia.org/wiki/Centaurus_A "Centaurus A") were released. With a mass around 5\.5×107 [M☉](https://en.wikipedia.org/wiki/Solar_mass "Solar mass"), the black hole is not large enough for its [photon sphere](https://en.wikipedia.org/wiki/Photon_sphere "Photon sphere") to be observed, as in EHT images of Messier M87\, but its jet extends even beyond its host galaxy while staying as a highly collimated beam which is a point of study. Edge-brightening of the jet was also observed which would exclude models of particle acceleration that are unable to reproduce this effect. The image was 16 times sharper than previous observations and utilized a 1.3 mm wavelength.[\[50\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-50)[\[51\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-51)[\[52\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-52) ### Sagittarius A\* \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=6 "Edit section: Sagittarius A")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/96/EHT_Saggitarius_A_black_hole.tif/lossy-page1-200px-EHT_Saggitarius_A_black_hole.tif.jpg)](https://en.wikipedia.org/wiki/File:EHT_Saggitarius_A_black_hole.tif) [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A* "Sagittarius A"), first image released in 2022 [![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Sagittarius_Astar_in_polarised_light.tif/lossy-page1-200px-Sagittarius_Astar_in_polarised_light.tif.jpg)](https://en.wikipedia.org/wiki/File:Sagittarius_Astar_in_polarised_light.tif) Sagittarius A\ in polarised light, image released in 2024 On May 12, 2022, the EHT Collaboration revealed an image of [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A"), the supermassive black hole at the [center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way") [galaxy](https://en.wikipedia.org/wiki/Galaxy "Galaxy"). The black hole is 27,000 light-years away from Earth; it is thousands of times smaller than M87\. [Sera Markoff](https://en.wikipedia.org/wiki/Sera_Markoff "Sera Markoff"), Co-Chair of the EHT Science Council, said: "We have two completely different types of galaxies and two very different black hole masses, but close to the edge of these black holes they look amazingly similar. This tells us that General Relativity governs these objects up close, and any differences we see further away must be due to differences in the material that surrounds the black holes."[\[53\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-53) On March 22, 2024, the EHT Collaboration released an image of Sagittarius A\* in polarized light.[\[54\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-54) ### J1924-2914 \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=7 "Edit section: J1924-2914")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e7/EHTj1924-2914.png/250px-EHTj1924-2914.png)](https://en.wikipedia.org/wiki/File:EHTj1924-2914.png) A multifrequency view of the bent jet in Blazar J1924-2914.[\[55\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:1-55)[\[56\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:2-56) In August 2022, the EHT together with Global Millimeter VLBI Array and the [Very Long Baseline Array](https://en.wikipedia.org/wiki/Very_Long_Baseline_Array "Very Long Baseline Array") imaged the distant [blazar](https://en.wikipedia.org/wiki/Blazar "Blazar") J1924-2914. They operated at 230 GHz, 86 GHz and 2.3+8.7 GHz, respectively, the highest angular resolution images of polarized emission from a quasar ever obtained. Observations reveal a helically bent jet and the polarization of its emission suggest a toroidal magnetic field structure. The object is used as calibrator for Sagittarius A\* sharing strong optical variability and polarization with it.[\[55\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:1-55)[\[56\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:2-56) ### NRAO 530 \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=8 "Edit section: NRAO 530")\] [![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/NRAO_530_by_EHT_01.jpg/250px-NRAO_530_by_EHT_01.jpg)](https://en.wikipedia.org/wiki/File:NRAO_530_by_EHT_01.jpg) NRAO 530 by EHT. The total intensity is shown in grayscale with black contours indicating 10%, 25%, 50%, and 75% of the peak LP intensity. Black dotted contours indicate 25%, 50%, and 75% of the peak polarized intensity. [![](https://upload.wikimedia.org/wikipedia/commons/thumb/7/77/NRAO_530_by_EHT_02.jpg/250px-NRAO_530_by_EHT_02.jpg)](https://en.wikipedia.org/wiki/File:NRAO_530_by_EHT_02.jpg) Schematic of the total-intensity and LP components in the EHT fiducial image of NRAO 530; white contours show the total intensity levels; color scale and cyan contours represent the polarized intensity of the method-averaged image. In February 2023, the EHT reported on the observations of the [quasar](https://en.wikipedia.org/wiki/Quasar "Quasar") NRAO 530. NRAO 530 (1730−130, J1733−1304) is a [flat-spectrum radio quasar](https://en.wikipedia.org/wiki/Flat-spectrum_radio_quasar "Flat-spectrum radio quasar") (FSRQ) that belongs to the class of bright γ-ray [blazars](https://en.wikipedia.org/wiki/Blazar "Blazar") and shows significant variability across the entire electromagnetic spectrum. The source was monitored by the University of Michigan Radio Observatory at 4.8, 8.4, and 14.5 GHz for several decades until 2012. The quasar underwent a dramatic radio outburst in 1997, during which its flux density at 14.5 GHz exceeded 10 Jy, while the average value is ~2 Jy. Since 2002, NRAO 530 has been monitored by the Submillimeter Array (SMA; Maunakea, Hawaii) at 1.3 mm and 870 μm. NRAO 530 has a redshift of z = 0.902 (Junkkarinen 1984), for which 100 μas corresponds to a linear distance of 6 billion pc. The source contains a supermassive black hole, the mass of which is currently uncertain, with estimates ranging from 3×108 M☉ to 2×109 M☉.[\[57\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-nrao530-57) It was observed with the Event Horizon Telescope on April 5−7, 2017, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A\. The observations were performed with the full EHT 2017 array of eight telescopes located at six geographical sites. At z* = 0.902, this is the most distant object imaged by the EHT so far. The team reconstructed the first images of the source at 230 GHz, at an angular resolution of about 20 μas, both in total intensity and in linear polarization (LP). Source variability was not detected, that allowed to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which was associated with the core. The feature is linearly polarized, with a fractional polarization of about 5%–8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle about −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field.[\[57\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-nrao530-57) ## Collaborating institutes \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=9 "Edit section: Collaborating institutes")\] The EHT Collaboration consists of 13 stakeholder institutes:[\[58\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-58) - the [Academia Sinica](https://en.wikipedia.org/wiki/Academia_Sinica "Academia Sinica") Institute of Astronomy and Astrophysics - the [University of Arizona](https://en.wikipedia.org/wiki/University_of_Arizona "University of Arizona") - the [University of Chicago](https://en.wikipedia.org/wiki/University_of_Chicago "University of Chicago") - the [East Asian Observatory](https://en.wikipedia.org/w/index.php?title=East_Asian_Observatory&action=edit&redlink=1 "East Asian Observatory (page does not exist)") - [Goethe University Frankfurt](https://en.wikipedia.org/wiki/Goethe_University_Frankfurt "Goethe University Frankfurt") - [Smithsonian Astrophysical Observatory](https://en.wikipedia.org/wiki/Smithsonian_Astrophysical_Observatory "Smithsonian Astrophysical Observatory") (part of the [Harvard–Smithsonian Center for Astrophysics](https://en.wikipedia.org/wiki/Harvard%E2%80%93Smithsonian_Center_for_Astrophysics "Harvard–Smithsonian Center for Astrophysics")) - [Institut de radioastronomie millimétrique](https://en.wikipedia.org/wiki/Institut_de_radioastronomie_millim%C3%A9trique "Institut de radioastronomie millimétrique") (IRAM, itself a collaboration between the French [CNRS](https://en.wikipedia.org/wiki/CNRS "CNRS"), the German [Max Planck Society](https://en.wikipedia.org/wiki/Max_Planck_Society "Max Planck Society"), and the Spanish [Instituto Geográfico Nacional](https://en.wikipedia.org/wiki/Instituto_Geogr%C3%A1fico_Nacional_\(Spain\) "Instituto Geográfico Nacional (Spain)")) - [Large Millimeter Telescope](https://en.wikipedia.org/wiki/Large_Millimeter_Telescope "Large Millimeter Telescope") Alfonso Serrano - [Max Planck Institute for Radio Astronomy](https://en.wikipedia.org/wiki/Max_Planck_Institute_for_Radio_Astronomy "Max Planck Institute for Radio Astronomy") - [MIT](https://en.wikipedia.org/wiki/MIT "MIT") [Haystack Observatory](https://en.wikipedia.org/wiki/Haystack_Observatory "Haystack Observatory") - [National Astronomical Observatory of Japan](https://en.wikipedia.org/wiki/National_Astronomical_Observatory_of_Japan "National Astronomical Observatory of Japan") - [Perimeter Institute for Theoretical Physics](https://en.wikipedia.org/wiki/Perimeter_Institute_for_Theoretical_Physics "Perimeter Institute for Theoretical Physics") - [Radboud University](https://en.wikipedia.org/wiki/Radboud_University "Radboud University") [![](https://upload.wikimedia.org/wikipedia/commons/thumb/1/10/Locations_of_the_telescopes_that_make_up_the_EHT_array_%28eso2208-eht-mwi%29.tiff/lossy-page1-1000px-Locations_of_the_telescopes_that_make_up_the_EHT_array_%28eso2208-eht-mwi%29.tiff.jpg)](https://en.wikipedia.org/wiki/File:Locations_of_the_telescopes_that_make_up_the_EHT_array_\(eso2208-eht-mwi\).tiff) Locations of the telescopes that make up the EHT array. A global map showing the radio observatories that form the Event Horizon Telescope (EHT) network used to image the Milky Way's central black hole, Sagittarius A\. The telescopes highlighted in yellow were part of the EHT network during the observations of Sagittarius A\ in 2017. These include the Atacama Large Millimeter/submillimeter Array (ALMA), the Atacama Pathfinder EXperiment (APEX), IRAM 30-meter telescope (30-M), James Clark Maxwell Telescope (JCMT), Large Millimeter Telescope (LMT), Submillimeter Array (SMA), Submillimetere Telescope (SMT) and South Pole Telescope (SPT). Highlighted in blue are the three telescopes added to the EHT Collaboration after 2018: the Greenland Telescope (GLT), the NOrthern Extended Millimeter Array (NOEMA) in France, and the University of Arizona ARO 12-meter Telescope at Kitt Peak. ## Funding \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=10 "Edit section: Funding")\] The EHT Collaboration receives funding from numerous sources including:[\[59\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-59) - [United States National Science Foundation](https://en.wikipedia.org/wiki/National_Science_Foundation "National Science Foundation") - [European Research Council](https://en.wikipedia.org/wiki/European_Research_Council "European Research Council") - [National Science and Technology Council of Taiwan](https://en.wikipedia.org/wiki/National_Science_and_Technology_Council_\(Taiwan\) "National Science and Technology Council (Taiwan)") (formerly Ministry of Science and Technology of Taiwan) - [Max Planck Society](https://en.wikipedia.org/wiki/Max_Planck_Society "Max Planck Society") - [Consejo Nacional de Ciencia y Technologia, Mexico](https://en.wikipedia.org/wiki/Consejo_Nacional_de_Ciencia_y_Tecnolog%C3%ADa_\(Mexico\) "Consejo Nacional de Ciencia y Tecnología (Mexico)") - [John Templeton Foundation](https://en.wikipedia.org/wiki/John_Templeton_Foundation "John Templeton Foundation") - [Gordon and Betty Moore Foundation](https://en.wikipedia.org/wiki/Gordon_and_Betty_Moore_Foundation "Gordon and Betty Moore Foundation") - [Japan Society for the Promotion of Science](https://en.wikipedia.org/wiki/Japan_Society_for_the_Promotion_of_Science "Japan Society for the Promotion of Science") - [Natural Sciences and Engineering Research Council of Canada](https://en.wikipedia.org/wiki/Natural_Sciences_and_Engineering_Research_Council "Natural Sciences and Engineering Research Council") - [Academia Sinica](https://en.wikipedia.org/wiki/Academia_Sinica "Academia Sinica") - [Smithsonian Institution](https://en.wikipedia.org/wiki/Smithsonian_Institution "Smithsonian Institution") Additionally, [Western Digital](https://en.wikipedia.org/wiki/Western_Digital "Western Digital") and [Xilinx](https://en.wikipedia.org/wiki/Xilinx "Xilinx") are industry donors.[\[60\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-60) ## References \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=11 "Edit section: References")\] 1. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-wp-2009_1-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-wp-2009_1-1) Doeleman, Sheperd (June 21, 2009). "Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole". Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers. 2010: 68. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0906\.3899](https://arxiv.org/abs/0906.3899). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2009astro2010S..68D](https://ui.adsabs.harvard.edu/abs/2009astro2010S..68D). 2. ^ [a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-1) [c](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-2) [d](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-3) [e](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-4) [f](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-5) The Event Horizon Telescope Collaboration (April 10, 2019). ["First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole"](https://doi.org/10.3847%2F2041-8213%2Fab0ec7). 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["Imaging optically-thin hotspots near the black hole horizon of Sgr A\ at radio and near-infrared wavelengths"](https://doi.org/10.1111%2Fj.1365-2966.2006.10152.x). Monthly Notices of the Royal Astronomical Society. 367 (3): 905–916\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0509237](https://arxiv.org/abs/astro-ph/0509237). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2006MNRAS.367..905B](https://ui.adsabs.harvard.edu/abs/2006MNRAS.367..905B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1111/j.1365-2966.2006.10152.x](https://doi.org/10.1111%2Fj.1365-2966.2006.10152.x). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [16881360](https://api.semanticscholar.org/CorpusID:16881360). 7. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-7) Balick, Bruce; Brown, R.L. (December 1, 1974). ["Intense sub-arcsecond structure in the galactic center"](https://doi.org/10.1086%2F153242). The Astrophysical Journal. 194 (1): 265–279\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1974ApJ...194..265B](https://ui.adsabs.harvard.edu/abs/1974ApJ...194..265B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/153242](https://doi.org/10.1086%2F153242). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [121802758](https://api.semanticscholar.org/CorpusID:121802758). 8. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-Sheperd2008_8-0) Doeleman, Sheperd (September 4, 2008). "Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre". Nature. 455 (7209): 78–80\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0809\.2442](https://arxiv.org/abs/0809.2442). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008Natur.455...78D](https://ui.adsabs.harvard.edu/abs/2008Natur.455...78D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature07245](https://doi.org/10.1038%2Fnature07245). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [18769434](https://pubmed.ncbi.nlm.nih.gov/18769434). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4424735](https://api.semanticscholar.org/CorpusID:4424735). 9. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-Sheperd2012_9-0) Doeleman, Sheperd (October 19, 2012). "Jet-launching structure resolved near the supermassive black hole in M87". Science. 338 (6105): 355–358\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1210\.6132](https://arxiv.org/abs/1210.6132). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2012Sci...338..355D](https://ui.adsabs.harvard.edu/abs/2012Sci...338..355D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1126/science.1224768](https://doi.org/10.1126%2Fscience.1224768). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [23019611](https://pubmed.ncbi.nlm.nih.gov/23019611). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [37585603](https://api.semanticscholar.org/CorpusID:37585603). 10. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-breakthrough-prize_10-0) ["Winners Of The 2020 Breakthrough Prize In Life Sciences, Fundamental Physics And Mathematics Announced"](https://breakthroughprize.org/News/54). Breakthrough Prize. Retrieved March 15, 2020. 11. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-website_11-0) ["Event Horizon Telescope 2022"](https://www.mpifr-bonn.mpg.de/announcements/2022/2). March 12, 2022. 12. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-apjl-focus_12-0) Shep Doeleman, on behalf of the EHT Collaboration (April 2019). ["Focus on the First Event Horizon Telescope Results"](https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT). The Astrophysical Journal Letters. Retrieved April 10, 2019. 13. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-NYT-20210324_13-0) [Overbye, Dennis](https://en.wikipedia.org/wiki/Dennis_Overbye "Dennis Overbye") (March 24, 2021). ["The Most Intimate Portrait Yet of a Black Hole – Two years of analyzing the polarized light from a galaxy's giant black hole has given scientists a glimpse at how quasars might arise"](https://www.nytimes.com/2021/03/24/science/astronomy-messier-87-black-hole.html). [The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times"). Retrieved March 25, 2021. 14. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-aasnova-20190410_14-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-aasnova-20190410_14-1) Kohler, Susanna (April 10, 2019). ["First Images of a Black Hole from the Event Horizon Telescope"](https://aasnova.org/2019/04/10/first-images-of-a-black-hole-from-the-event-horizon-telescope/). AAS Nova. Retrieved April 10, 2019. 15. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-NYT-20220512_15-0)* [Overbye, Dennis](https://en.wikipedia.org/wiki/Dennis_Overbye "Dennis Overbye") (May 12, 2022). ["Has the Milky Way's Black Hole Come to Light? – The Event Horizon Telescope reaches again for a glimpse of the 'unseeable'"](https://www.nytimes.com/2022/05/12/science/black-hole-photo.html). [The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times"). Retrieved May 12, 2022. 16. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-16) Alexander W. Raymond et al 2024 AJ 168 130 17. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-O'Neil2015_17-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-O'Neil2015_17-1) O'Neill, Ian (July 2, 2015). ["Event Horizon Telescope Will Probe Spacetime's Mysteries"](https://web.archive.org/web/20150905193743/http://news.discovery.com/space/astronomy/event-horizon-telescope-will-probe-spacetimes-mysteries-150702.htm). Discovery News. Archived from [the original](http://news.discovery.com/space/astronomy/event-horizon-telescope-will-probe-spacetimes-mysteries-150702.htm) on September 5, 2015. Retrieved August 21, 2015. 18. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-18)* ["MIT Haystack Observatory: Astronomy Wideband VLBI Millimeter Wavelength"](https://www.haystack.mit.edu/ast/uvlbi/mm/eht.html). www.haystack.mit.edu. 19. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-19) Webb, Jonathan (January 8, 2016). ["Event horizon snapshot due in 2017"](https://www.bbc.com/news/science-environment-35258378). BBC News. Retrieved March 24, 2016. 20. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-nature543_20-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-nature543_20-1) Davide Castelvecchi (March 23, 2017). ["How to hunt for a black hole with a telescope the size of Earth"](https://doi.org/10.1038%2F543478a). Nature. 543* (7646): 478–480\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2017Natur.543..478C](https://ui.adsabs.harvard.edu/abs/2017Natur.543..478C). 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Retrieved September 27, 2023. ## External links \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=12 "Edit section: External links")\] [![](https://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/40px-Commons-logo.svg.png)](https://en.wikipedia.org/wiki/File:Commons-logo.svg) Wikimedia Commons has media related to [Event Horizon Telescope](https://commons.wikimedia.org/wiki/Category:Event_Horizon_Telescope "commons:Category:Event Horizon Telescope"). - [Official website](https://eventhorizontelescope.org/) [![Edit this at Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q3944788#P856 "Edit this at Wikidata") - [EHT "Ask Me Anything" (AMA) serie](https://www.reddit.com/r/askscience/comments/olel36/askscience_ama_series_were_event_horizon_horizon/) on [reddit](https://en.wikipedia.org/wiki/Reddit "Reddit") - [The Next Generation Event Horizon Telescope](https://www.ngeht.org/) \| [v](https://en.wikipedia.org/wiki/Template:Radio_astronomy "Template:Radio astronomy") [t](https://en.wikipedia.org/wiki/Template_talk:Radio_astronomy "Template talk:Radio astronomy") [e](https://en.wikipedia.org/wiki/Special:EditPage/Template:Radio_astronomy "Special:EditPage/Template:Radio astronomy")[Radio astronomy](https://en.wikipedia.org/wiki/Radio_astronomy "Radio astronomy") \| \| \|---\|---\| \| Concepts \| Units ([watt](https://en.wikipedia.org/wiki/Watt "Watt") and [jansky](https://en.wikipedia.org/wiki/Jansky "Jansky")) [Radio telescope](https://en.wikipedia.org/wiki/Radio_telescope "Radio telescope") ([Radio window](https://en.wikipedia.org/wiki/Radio_window "Radio window")) [Astronomical interferometer](https://en.wikipedia.org/wiki/Astronomical_interferometer "Astronomical interferometer") ([History](https://en.wikipedia.org/wiki/Astronomical_interferometer#History "Astronomical interferometer")) [Very Long Baseline Interferometry](https://en.wikipedia.org/wiki/Very-long-baseline_interferometry "Very-long-baseline interferometry") (VLBI) [Astronomical radio source](https://en.wikipedia.org/wiki/Astronomical_radio_source "Astronomical radio source") \| \| [Radio telescopes](https://en.wikipedia.org/wiki/Category:Radio_telescopes "Category:Radio telescopes") ([List](https://en.wikipedia.org/wiki/List_of_radio_telescopes "List of radio telescopes")) \| \| \| \| \| \| Individual telescopes \| [500 meter Aperture Spherical Telescope](https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Spherical_Telescope "Five-hundred-meter Aperture Spherical Telescope") (FAST, China) [Arecibo Telescope](https://en.wikipedia.org/wiki/Arecibo_Telescope "Arecibo Telescope") (Puerto Rico, US) [Caltech Submillimeter Observatory](https://en.wikipedia.org/wiki/Caltech_Submillimeter_Observatory "Caltech Submillimeter Observatory") (CSO, US) [Effelsberg Telescope](https://en.wikipedia.org/wiki/Effelsberg_100-m_Radio_Telescope "Effelsberg 100-m Radio Telescope") (Germany) [Galenki RT-70](https://en.wikipedia.org/wiki/Galenki_RT-70_radio_telescope "Galenki RT-70 radio telescope") (Russia) [Green Bank Telescope](https://en.wikipedia.org/wiki/Green_Bank_Telescope "Green Bank Telescope") (West Virginia, US) [Large Millimeter Telescope](https://en.wikipedia.org/wiki/Large_Millimeter_Telescope "Large Millimeter Telescope") (Mexico) [Lovell Telescope](https://en.wikipedia.org/wiki/Lovell_Telescope "Lovell Telescope") (UK) [Ooty Telescope](https://en.wikipedia.org/wiki/Ooty_Radio_Telescope "Ooty Radio Telescope") (India) [Qitai Radio Telescope](https://en.wikipedia.org/wiki/Qitai_Radio_Telescope "Qitai Radio Telescope") (China) [RATAN-600 Radio Telescope](https://en.wikipedia.org/wiki/RATAN-600 "RATAN-600") (Russia) [Sardinia Radio Telescope](https://en.wikipedia.org/wiki/Sardinia_Radio_Telescope "Sardinia Radio Telescope") (Italy) [Suffa RT-70](https://en.wikipedia.org/wiki/Suffa_RT-70_radio_telescope "Suffa RT-70 radio telescope") (Uzbekistan) [Usuda Telescope](https://en.wikipedia.org/wiki/Usuda_Deep_Space_Center "Usuda Deep Space Center") (Japan) [UTR-2 decameter radio telescope](https://en.wikipedia.org/wiki/Ukrainian_T-shaped_Radio_telescope,_second_modification "Ukrainian T-shaped Radio telescope, second modification") (Ukraine) [Yevpatoria RT-70](https://en.wikipedia.org/wiki/Yevpatoria_RT-70_radio_telescope "Yevpatoria RT-70 radio telescope") (Ukraine) Southern Hemisphere [HartRAO](https://en.wikipedia.org/wiki/Hartebeesthoek_Radio_Astronomy_Observatory "Hartebeesthoek Radio Astronomy Observatory") (South Africa) [Parkes Observatory](https://en.wikipedia.org/wiki/Parkes_Observatory "Parkes Observatory") (Australia) [Warkworth Radio Astronomical Observatory](https://en.wikipedia.org/wiki/Warkworth_Radio_Astronomical_Observatory "Warkworth Radio Astronomical Observatory") (NZ) \| \| Interferometers \| [Allen Telescope Array](https://en.wikipedia.org/wiki/Allen_Telescope_Array "Allen Telescope Array") (ATA, California, US) [Atacama Large Millimeter Array](https://en.wikipedia.org/wiki/Atacama_Large_Millimeter_Array "Atacama Large Millimeter Array") (ALMA, Chile) [Australia Telescope Compact Array](https://en.wikipedia.org/wiki/Australia_Telescope_Compact_Array "Australia Telescope Compact Array") (ATCA, Australia) [Australian Square Kilometre Array Pathfinder](https://en.wikipedia.org/wiki/Australian_Square_Kilometre_Array_Pathfinder "Australian Square Kilometre Array Pathfinder") (ASKAP, Australia) [Canadian Hydrogen Intensity Mapping Experiment](https://en.wikipedia.org/wiki/Canadian_Hydrogen_Intensity_Mapping_Experiment "Canadian Hydrogen Intensity Mapping Experiment") (CHIME, Canada) [Combined Array for Research in Millimeter-wave Astronomy](https://en.wikipedia.org/wiki/Combined_Array_for_Research_in_Millimeter-wave_Astronomy "Combined Array for Research in Millimeter-wave Astronomy") (CARMA, California, US) [European VLBI Network](https://en.wikipedia.org/wiki/European_VLBI_Network "European VLBI Network") (Europe) [Event Horizon Telescope]() (EHT) [Giant Metrewave Radio Telescope](https://en.wikipedia.org/wiki/Giant_Metrewave_Radio_Telescope "Giant Metrewave Radio Telescope") (GMRT, India) [Green Bank Interferometer](https://en.wikipedia.org/wiki/Green_Bank_Interferometer "Green Bank Interferometer") (GBI, West Virginia, US) [Korean VLBI Network](https://en.wikipedia.org/wiki/Korean_VLBI_Network "Korean VLBI Network") (KVN, South Korea) [Large Latin American Millimeter Array](https://en.wikipedia.org/wiki/Large_Latin_American_Millimeter_Array "Large Latin American Millimeter Array") (LLAMA, Argentina/Brazil) [Long Wavelength Array](https://en.wikipedia.org/wiki/Long_Wavelength_Array "Long Wavelength Array") (LWA, New Mexico, US) [Low-Frequency Array](https://en.wikipedia.org/wiki/Low-Frequency_Array_\(LOFAR\) "Low-Frequency Array (LOFAR)") (LOFAR, Netherlands) [MeerKAT](https://en.wikipedia.org/wiki/MeerKAT "MeerKAT") (South Africa) [Molonglo Observatory Synthesis Telescope](https://en.wikipedia.org/wiki/Molonglo_Observatory_Synthesis_Telescope "Molonglo Observatory Synthesis Telescope") (MOST, Australia) [Multi-Element Radio Linked Interferometer Network](https://en.wikipedia.org/wiki/MERLIN "MERLIN") (MERLIN, UK) [Murchison Widefield Array](https://en.wikipedia.org/wiki/Murchison_Widefield_Array "Murchison Widefield Array") (MWA, Australia) [Northern Cross Radio Telescope](https://en.wikipedia.org/wiki/Northern_Cross_Radio_Telescope "Northern Cross Radio Telescope") (Italy) [Northern Extended Millimeter Array](https://en.wikipedia.org/wiki/Northern_Extended_Millimeter_Array "Northern Extended Millimeter Array") (France) [One-Mile Telescope](https://en.wikipedia.org/wiki/One-Mile_Telescope "One-Mile Telescope") (UK) [Primeval Structure Telescope](https://en.wikipedia.org/wiki/Primeval_Structure_Telescope "Primeval Structure Telescope") (PaST, China) [Square Kilometre Array](https://en.wikipedia.org/wiki/Square_Kilometre_Array "Square Kilometre Array") (SKA, Australia, South Africa) [Submillimeter Array](https://en.wikipedia.org/wiki/Submillimeter_Array "Submillimeter Array") (SMA, US) [Very Large Array](https://en.wikipedia.org/wiki/Very_Large_Array "Very Large Array") (VLA, New Mexico, US) [Very Long Baseline Array](https://en.wikipedia.org/wiki/Very_Long_Baseline_Array "Very Long Baseline Array") (VLBA, US) [Westerbork Synthesis Radio Telescope](https://en.wikipedia.org/wiki/Westerbork_Synthesis_Radio_Telescope "Westerbork Synthesis Radio Telescope") (WSRT, Netherlands) \| \| Space-based \| [HALCA](https://en.wikipedia.org/wiki/HALCA "HALCA") (Japan) [Spektr-R](https://en.wikipedia.org/wiki/Spektr-R "Spektr-R") (Russia) \| \| [Observatories](https://en.wikipedia.org/wiki/Category:Radio_observatories "Category:Radio observatories") \| [Algonquin Radio Observatory](https://en.wikipedia.org/wiki/Algonquin_Radio_Observatory "Algonquin Radio Observatory") (Canada) [Arecibo Observatory](https://en.wikipedia.org/wiki/Arecibo_Observatory "Arecibo Observatory") (Puerto Rico, US) [Green Bank Observatory](https://en.wikipedia.org/wiki/Green_Bank_Observatory "Green Bank Observatory") (US) [Haystack Observatory](https://en.wikipedia.org/wiki/Haystack_Observatory "Haystack Observatory") (US) [Jodrell Bank Observatory](https://en.wikipedia.org/wiki/Jodrell_Bank_Observatory "Jodrell Bank Observatory") (UK) [Mullard Radio Astronomy Observatory](https://en.wikipedia.org/wiki/Mullard_Radio_Astronomy_Observatory "Mullard Radio Astronomy Observatory") (UK) [National Radio Astronomy Observatory](https://en.wikipedia.org/wiki/National_Radio_Astronomy_Observatory "National Radio Astronomy Observatory") (US) [Nançay Radio Observatory](https://en.wikipedia.org/wiki/Nan%C3%A7ay_Radio_Observatory "Nançay Radio Observatory") (France) [Onsala Space Observatory](https://en.wikipedia.org/wiki/Onsala_Space_Observatory "Onsala Space Observatory") (Sweden) [Pushchino Radio Astronomy Observatory](https://en.wikipedia.org/wiki/Pushchino_Radio_Astronomy_Observatory "Pushchino Radio Astronomy Observatory") (PRAO ASC LPI, Russia) [Special Astrophysical Observatory of the Russian Academy of Science](https://en.wikipedia.org/wiki/Special_Astrophysical_Observatory_of_the_Russian_Academy_of_Science "Special Astrophysical Observatory of the Russian Academy of Science") (SAORAS, Russia) [Vermilion River Observatory](https://en.wikipedia.org/wiki/Vermilion_River_Observatory "Vermilion River Observatory") (US) \| \| Multi-use \| [DRAO](https://en.wikipedia.org/wiki/Dominion_Radio_Astrophysical_Observatory "Dominion Radio Astrophysical Observatory") (Canada) [ESA New Norcia](https://en.wikipedia.org/wiki/New_Norcia_Station "New Norcia Station") (Australia) [PARL](https://en.wikipedia.org/wiki/Prince_Albert_Radar_Laboratory "Prince Albert Radar Laboratory") (Canada) \| \| People \| [Elizabeth Alexander](https://en.wikipedia.org/wiki/Elizabeth_Alexander_\(scientist\) "Elizabeth Alexander (scientist)") [John G. Bolton](https://en.wikipedia.org/wiki/John_Gatenby_Bolton "John Gatenby Bolton") [Edward George Bowen](https://en.wikipedia.org/wiki/Edward_George_Bowen "Edward George Bowen") [Ronald Bracewell](https://en.wikipedia.org/wiki/Ronald_N._Bracewell "Ronald N. Bracewell") [Jocelyn Bell Burnell](https://en.wikipedia.org/wiki/Jocelyn_Bell_Burnell "Jocelyn Bell Burnell") [Arthur Covington](https://en.wikipedia.org/wiki/Arthur_Covington "Arthur Covington") [Nan Dieter-Conklin](https://en.wikipedia.org/wiki/Nan_Dieter-Conklin "Nan Dieter-Conklin") [Frank Drake](https://en.wikipedia.org/wiki/Frank_Drake "Frank Drake") [Cyril Hazard](https://en.wikipedia.org/wiki/Cyril_Hazard "Cyril Hazard") [Antony Hewish](https://en.wikipedia.org/wiki/Antony_Hewish "Antony Hewish") [Sebastian von Hoerner](https://en.wikipedia.org/wiki/Sebastian_von_Hoerner "Sebastian von Hoerner") [Karl Guthe Jansky](https://en.wikipedia.org/wiki/Karl_Guthe_Jansky "Karl Guthe Jansky") [Kenneth Kellermann](https://en.wikipedia.org/wiki/Kenneth_Kellermann "Kenneth Kellermann") [Frank J. Kerr](https://en.wikipedia.org/wiki/Frank_John_Kerr "Frank John Kerr") [John D. Kraus](https://en.wikipedia.org/wiki/John_D._Kraus "John D. Kraus") [Bernard Lovell](https://en.wikipedia.org/wiki/Bernard_Lovell "Bernard Lovell") [Christiaan Alexander Muller](https://en.wikipedia.org/wiki/Christiaan_Alexander_Muller "Christiaan Alexander Muller") [Jan Oort](https://en.wikipedia.org/wiki/Jan_Oort "Jan Oort") [Joseph Lade Pawsey](https://en.wikipedia.org/wiki/Joseph_L._Pawsey "Joseph L. Pawsey") [Ruby Payne-Scott](https://en.wikipedia.org/wiki/Ruby_Payne-Scott "Ruby Payne-Scott") [Arno Penzias](https://en.wikipedia.org/wiki/Arno_Allan_Penzias "Arno Allan Penzias") [Grote Reber](https://en.wikipedia.org/wiki/Grote_Reber "Grote Reber") [Martin Ryle](https://en.wikipedia.org/wiki/Martin_Ryle "Martin Ryle") [Govind Swarup](https://en.wikipedia.org/wiki/Govind_Swarup "Govind Swarup") [Gart Westerhout](https://en.wikipedia.org/wiki/Gart_Westerhout "Gart Westerhout") [Paul Wild](https://en.wikipedia.org/wiki/Paul_Wild_\(Australian_scientist\) "Paul Wild (Australian scientist)") [Robert Wilson](https://en.wikipedia.org/wiki/Robert_Woodrow_Wilson "Robert Woodrow Wilson") \| \| Astronomy by EM methods \| [Submillimetre astronomy](https://en.wikipedia.org/wiki/Submillimetre_astronomy "Submillimetre astronomy") [Infrared astronomy](https://en.wikipedia.org/wiki/Infrared_astronomy "Infrared astronomy") [Optical astronomy](https://en.wikipedia.org/wiki/Visible-light_astronomy "Visible-light astronomy") [High-energy astronomy](https://en.wikipedia.org/wiki/High-energy_astronomy "High-energy astronomy") [Gravitational-wave astronomy](https://en.wikipedia.org/wiki/Gravitational-wave_astronomy "Gravitational-wave astronomy") \| \| Related articles \| [Aperture synthesis](https://en.wikipedia.org/wiki/Aperture_synthesis "Aperture synthesis") [Cosmic microwave background radiation](https://en.wikipedia.org/wiki/Cosmic_microwave_background "Cosmic microwave background") [Interferometry](https://en.wikipedia.org/wiki/Interferometry "Interferometry") [Odd radio circle](https://en.wikipedia.org/wiki/Odd_radio_circle "Odd radio circle") [Pulsar timing array](https://en.wikipedia.org/wiki/Pulsar_timing_array "Pulsar timing array") [Radio propagation](https://en.wikipedia.org/wiki/Radio_propagation "Radio propagation") [SETI](https://en.wikipedia.org/wiki/Search_for_extraterrestrial_intelligence "Search for extraterrestrial intelligence") [Wow! signal](https://en.wikipedia.org/wiki/Wow!_signal "Wow! signal") [HD 164595 signal](https://en.wikipedia.org/wiki/HD_164595 "HD 164595") [Solar radio emission](https://en.wikipedia.org/wiki/Solar_radio_emission "Solar radio emission") \| \| ![](https://upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/20px-Symbol_category_class.svg.png) [Category](https://en.wikipedia.org/wiki/Category:Radio_astronomy "Category:Radio astronomy") [![](https://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/20px-Commons-logo.svg.png)](https://en.wikipedia.org/wiki/File:Commons-logo.svg "Commons page") [Commons](https://commons.wikimedia.org/wiki/Category:Radio_astronomy "commons:Category:Radio astronomy") \| \| [Portals](https://en.wikipedia.org/wiki/Wikipedia:Contents/Portals "Wikipedia:Contents/Portals"): - ![](https://upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/20px-Crab_Nebula.jpg) [Astronomy](https://en.wikipedia.org/wiki/Portal:Astronomy "Portal:Astronomy") - [![icon](https://upload.wikimedia.org/wikipedia/commons/thumb/5/5f/He1523a.jpg/20px-He1523a.jpg)](https://en.wikipedia.org/wiki/File:He1523a.jpg) [Stars](https://en.wikipedia.org/wiki/Portal:Stars "Portal:Stars") - ![](https://upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/40px-Earth-moon.jpg) [Outer space](https://en.wikipedia.org/wiki/Portal:Outer_space "Portal:Outer space") ![](https://en.wikipedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=1) Retrieved from "<https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&oldid=1341248860>" [Categories](https://en.wikipedia.org/wiki/Help:Category "Help:Category"): - [Interferometric telescopes](https://en.wikipedia.org/wiki/Category:Interferometric_telescopes "Category:Interferometric telescopes") - [Albert Einstein Medal recipients](https://en.wikipedia.org/wiki/Category:Albert_Einstein_Medal_recipients "Category:Albert Einstein Medal recipients") Hidden categories: - [Articles with short description](https://en.wikipedia.org/wiki/Category:Articles_with_short_description "Category:Articles with short description") - [Short description is different from Wikidata](https://en.wikipedia.org/wiki/Category:Short_description_is_different_from_Wikidata "Category:Short description is different from Wikidata") - [Use American English from April 2019](https://en.wikipedia.org/wiki/Category:Use_American_English_from_April_2019 "Category:Use American English from April 2019") - [All Wikipedia articles written in American English](https://en.wikipedia.org/wiki/Category:All_Wikipedia_articles_written_in_American_English "Category:All Wikipedia articles written in American English") - [Use mdy dates from April 2019](https://en.wikipedia.org/wiki/Category:Use_mdy_dates_from_April_2019 "Category:Use mdy dates from April 2019") - [Pages using infobox mapframe with missing coordinates](https://en.wikipedia.org/wiki/Category:Pages_using_infobox_mapframe_with_missing_coordinates "Category:Pages using infobox mapframe with missing coordinates") - [Articles using Infobox observatory using locally defined parameters](https://en.wikipedia.org/wiki/Category:Articles_using_Infobox_observatory_using_locally_defined_parameters "Category:Articles using Infobox observatory using locally defined parameters") - [Pages using multiple image with unknown parameters](https://en.wikipedia.org/wiki/Category:Pages_using_multiple_image_with_unknown_parameters "Category:Pages using multiple image with unknown parameters") - [Commons category link from Wikidata](https://en.wikipedia.org/wiki/Category:Commons_category_link_from_Wikidata "Category:Commons category link from Wikidata") - This page was last edited on 2 March 2026, at 04:38 (UTC). - Text is available under the [Creative Commons Attribution-ShareAlike 4.0 License](https://en.wikipedia.org/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License "Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License"); additional terms may apply. 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Readable Markdown	From Wikipedia, the free encyclopedia \| \| \| \|---\|---\| \| [![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/35/Event_Horizon_Telescope.svg/250px-Event_Horizon_Telescope.svg.png)](https://en.wikipedia.org/wiki/File:Event_Horizon_Telescope.svg) \| \| \| Alternative names \| EHT [![Edit this on Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q3944788?uselang=en#P1813 "Edit this on Wikidata") \| \| Established \| 2009; 17 years ago \| \| Website \| [eventhorizontelescope.org](https://eventhorizontelescope.org/) [![Edit this at Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q3944788#P856 "Edit this at Wikidata") \| \| Telescopes \| [Atacama Large Millimeter Array](https://en.wikipedia.org/wiki/Atacama_Large_Millimeter_Array "Atacama Large Millimeter Array") [Atacama Pathfinder Experiment](https://en.wikipedia.org/wiki/Atacama_Pathfinder_Experiment "Atacama Pathfinder Experiment") [Greenland Telescope](https://en.wikipedia.org/wiki/Greenland_Telescope "Greenland Telescope") [Heinrich Hertz Submillimeter Telescope](https://en.wikipedia.org/wiki/Heinrich_Hertz_Submillimeter_Telescope "Heinrich Hertz Submillimeter Telescope") [IRAM 30m telescope](https://en.wikipedia.org/wiki/IRAM_30m_telescope "IRAM 30m telescope") [James Clerk Maxwell Telescope](https://en.wikipedia.org/wiki/James_Clerk_Maxwell_Telescope "James Clerk Maxwell Telescope") [Large Millimeter Telescope](https://en.wikipedia.org/wiki/Large_Millimeter_Telescope "Large Millimeter Telescope") [South Pole Telescope](https://en.wikipedia.org/wiki/South_Pole_Telescope "South Pole Telescope") [Submillimeter Array](https://en.wikipedia.org/wiki/Submillimeter_Array "Submillimeter Array") [![Edit this on Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q3944788?uselang=en#P527 "Edit this on Wikidata") \| \| [![](https://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/20px-Commons-logo.svg.png)](https://en.wikipedia.org/wiki/File:Commons-logo.svg) [Related media on Commons](https://commons.wikimedia.org/wiki/Category:Event_Horizon_Telescope "commons:Category:Event Horizon Telescope") \| \| \| \[[edit on Wikidata](https://www.wikidata.org/wiki/Q3944788 "d:Q3944788")\] \| \| The Event Horizon Telescope (EHT) is a [telescope array](https://en.wikipedia.org/wiki/Astronomical_interferometer "Astronomical interferometer") consisting of a global network of [radio telescopes](https://en.wikipedia.org/wiki/Radio_telescope "Radio telescope"). The EHT project combines data from several [very-long-baseline interferometry](https://en.wikipedia.org/wiki/Very-long-baseline_interferometry "Very-long-baseline interferometry") (VLBI) stations around Earth, which form a combined array with an [angular resolution](https://en.wikipedia.org/wiki/Angular_resolution "Angular resolution") sufficient to observe objects the size of a [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole")'s [event horizon](https://en.wikipedia.org/wiki/Event_horizon "Event horizon"). The project's observational targets include the two [black holes](https://en.wikipedia.org/wiki/Black_hole "Black hole") with the largest [angular diameter](https://en.wikipedia.org/wiki/Angular_diameter "Angular diameter") as observed from Earth: the black hole at the center of the [supergiant](https://en.wikipedia.org/wiki/Type-cD_galaxy "Type-cD galaxy") [elliptical galaxy](https://en.wikipedia.org/wiki/Elliptical_galaxy "Elliptical galaxy") [Messier 87](https://en.wikipedia.org/wiki/Messier_87 "Messier 87"), and [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A"), at [the center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way").[\[1\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-wp-2009-1)[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2) The Event Horizon Telescope project is an international collaboration that was launched in 2009[\[1\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-wp-2009-1) after a long period of theoretical and technical developments. On the theory side, work on the photon orbit[\[3\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-3) and first simulations of what a black hole would look like[\[4\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-4) progressed to predictions of VLBI imaging for the Galactic Center black hole, Sgr A\.[\[5\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:0-5)[\[6\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:0a-6) Technical advances in radio observing moved from the first detection of Sgr A\,[\[7\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-7) through VLBI at progressively shorter wavelengths, ultimately leading to detection of horizon scale structure in both Sgr A\ and M87.[\[8\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-Sheperd2008-8)[\[9\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-Sheperd2012-9) The collaboration now comprises over 300[\[10\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-breakthrough-prize-10) members, and 60 institutions, working in over 20 countries and regions.[\[11\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-website-11) The first image of a black hole, at the center of galaxy Messier 87, was published by the EHT Collaboration on April 10, 2019, in a series of six scientific publications.[\[12\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eht-apjl-focus-12) The array made this observation at a wavelength of 1.3 mm and with a theoretical [diffraction-limited resolution](https://en.wikipedia.org/wiki/Diffraction-limited_resolution "Diffraction-limited resolution") of 25 [microarcseconds](https://en.wikipedia.org/wiki/Microarcsecond "Microarcsecond"). In March 2021, the Collaboration presented, for the first time, a [polarized-based image](https://en.wikipedia.org/wiki/Polarization_\(waves\) "Polarization (waves)") of the [black hole](https://en.wikipedia.org/wiki/Black_hole "Black hole") which may help better reveal the forces giving rise to [quasars](https://en.wikipedia.org/wiki/Quasar "Quasar").[\[13\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20210324-13) Future plans involve improving the array's resolution by adding new telescopes and by taking shorter-wavelength observations.[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[14\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-aasnova-20190410-14) On 12 May 2022, astronomers unveiled the first image of the supermassive black hole at the center of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way"), [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A").[\[15\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20220512-15) Since 2018 the EHT has been capable of imaging at a wavelength of 870 μm (345 GHz), giving an angular resolution of 19 μas, the best resolution of any ground-based telescope.[\[16\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-16) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/1/13/EHT-infography.png/250px-EHT-infography.png)](https://en.wikipedia.org/wiki/File:EHT-infography.png) A schematic diagram of the VLBI mechanism of EHT. Each antenna, spread out over vast distances, has an extremely precise [atomic clock](https://en.wikipedia.org/wiki/Atomic_clock "Atomic clock"). [Analogue signals](https://en.wikipedia.org/wiki/Analog_signal "Analog signal") collected by the antenna are converted to [digital signals](https://en.wikipedia.org/wiki/Digital_signal "Digital signal") and stored on hard drives together with the time signals provided by the atomic clock. The hard drives are then shipped to a central location to be synchronized. An astronomical observation image is obtained by processing the data gathered from multiple locations. [![](https://upload.wikimedia.org/wikipedia/commons/thumb/2/23/EHTobservations2017.jpg/250px-EHTobservations2017.jpg)](https://en.wikipedia.org/wiki/File:EHTobservations2017.jpg) EHT observations during its 2017 M87 multiwavelength campaign decomposed by instrument from lower (EHT/ALMA/SMA) to higher (VERITAS) frequency. (Fermi-LAT in continuous survey mode) (dates also in [Modified Julian days](https://en.wikipedia.org/wiki/Julian_day#Variants "Julian day")) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Sagittarius_A%2A.jpg/250px-Sagittarius_A%2A.jpg)](https://en.wikipedia.org/wiki/File:Sagittarius_A.jpg) Soft [X-ray](https://en.wikipedia.org/wiki/X-ray "X-ray") image of [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A") (center) and two [light echoes](https://en.wikipedia.org/wiki/Light_echo "Light echo") from a recent explosion (circled) The EHT is composed of many radio observatories or radio-telescope facilities around the world, working together to produce a high-sensitivity, high-angular-resolution telescope. Through the technique of [very-long-baseline interferometry](https://en.wikipedia.org/wiki/Very-long-baseline_interferometry "Very-long-baseline interferometry") (VLBI), many independent radio antennas separated by hundreds or thousands of kilometres can act as a [phased array](https://en.wikipedia.org/wiki/Phased_array "Phased array"), a virtual telescope which can be pointed electronically, with an [effective aperture](https://en.wikipedia.org/wiki/Aperture_synthesis "Aperture synthesis") which is the diameter of the entire planet, substantially improving its angular resolution.[\[17\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-O'Neil2015-17) The effort includes development and deployment of [submillimeter](https://en.wikipedia.org/wiki/Submillimetre_astronomy "Submillimetre astronomy") dual [polarization](https://en.wikipedia.org/wiki/Polarization_\(waves\) "Polarization (waves)") receivers, highly stable frequency standards to enable very-long-baseline interferometry at 230–450 GHz, higher-bandwidth VLBI backends and recorders, as well as commissioning of new submillimeter VLBI sites.[\[18\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-18) Each year since its first data capture in 2006, the EHT array has moved to add more observatories to its global network of radio telescopes. The first image of the Milky Way's supermassive black hole, Sagittarius A\, was expected to be produced from data taken in April 2017,[\[19\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-19)[\[20\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-nature543-20) but because there are no flights in or out of the South Pole during austral winter (April to October), the full data set could not be processed until December 2017, when the shipment of data from the [South Pole Telescope](https://en.wikipedia.org/wiki/South_Pole_Telescope "South Pole Telescope") arrived.[\[21\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-21) Data collected on hard drives are transported by commercial freight airplanes[\[22\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-22) (a so-called [sneakernet](https://en.wikipedia.org/wiki/Sneakernet "Sneakernet")) from the various telescopes to the [MIT](https://en.wikipedia.org/wiki/MIT "MIT") [Haystack Observatory](https://en.wikipedia.org/wiki/Haystack_Observatory "Haystack Observatory") and the [Max Planck Institute for Radio Astronomy](https://en.wikipedia.org/wiki/Max_Planck_Institute_for_Radio_Astronomy "Max Planck Institute for Radio Astronomy"), where the data are [cross-correlated](https://en.wikipedia.org/wiki/Cross-correlation "Cross-correlation") and analyzed on a [grid computer](https://en.wikipedia.org/wiki/Grid_computing "Grid computing") made from about 800 [CPUs](https://en.wikipedia.org/wiki/Central_processing_unit "Central processing unit") all connected through a 40 Gbit/s network.[\[23\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-23) Because of the [COVID-19 pandemic](https://en.wikipedia.org/wiki/COVID-19_pandemic "COVID-19 pandemic"), weather patterns, and celestial mechanics, the 2020 observational campaign was postponed to March 2021.[\[24\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-24) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Event_Horizon_Telescope_and_Apollo_16.png/250px-Event_Horizon_Telescope_and_Apollo_16.png)](https://en.wikipedia.org/wiki/File:Event_Horizon_Telescope_and_Apollo_16.png) A series of images descriptive of the level of magnification achieved by the EHT (akin to seeing, from the Earth's surface, an object the size of a tennis ball on the Moon); starts at top-left image and moves counter−clockwise to finish at top-right corner [![](https://upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Black_hole_-_Messier_87_crop_max_res.jpg/250px-Black_hole_-_Messier_87_crop_max_res.jpg)](https://en.wikipedia.org/wiki/File:Black_hole_-_Messier_87_crop_max_res.jpg) Image of [M87\](https://en.wikipedia.org/wiki/M87 "M87") generated from data gathered by the Event Horizon Telescope[\[25\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20190410-25)[\[26\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NASA-20190410-26) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif/lossy-page1-250px-A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif.jpg)](https://en.wikipedia.org/wiki/File:A_view_of_the_M87_supermassive_black_hole_in_polarised_light.tif) A view of [M87\](https://en.wikipedia.org/wiki/M87* "M87") black hole in polarised light The Event Horizon Telescope Collaboration announced its first results in six simultaneous press conferences worldwide on April 10, 2019.[\[25\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20190410-25)[\[26\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NASA-20190410-26)[\[27\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-27) The announcement featured the first direct image of a black hole, which showed the [supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole "Supermassive black hole") at the center of [Messier 87](https://en.wikipedia.org/wiki/Messier_87 "Messier 87"), designated M87\.[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[28\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NS-name-28)[\[29\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20190412-29) The scientific results were presented in a series of six papers published in [The Astrophysical Journal Letters](https://en.wikipedia.org/wiki/The_Astrophysical_Journal_Letters "The Astrophysical Journal Letters").[\[30\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eso1907-30) A clockwise [rotating black hole](https://en.wikipedia.org/wiki/Rotating_black_hole "Rotating black hole") was observed in the 6σ region.[\[31\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-RotBlackHole-31) The image provided a test for [Albert Einstein](https://en.wikipedia.org/wiki/Albert_Einstein "Albert Einstein")'s [general theory of relativity](https://en.wikipedia.org/wiki/General_relativity "General relativity") under extreme conditions.[\[17\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-O'Neil2015-17)[\[20\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-nature543-20) Studies have previously tested general relativity by looking at the motions of stars and gas clouds near the edge of a black hole. However, an image of a black hole brings observations even closer to the event horizon.[\[32\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-sciencenews-32) Relativity predicts a dark shadow-like region, caused by gravitational bending and capture of light,[\[5\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:0-5)[\[6\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:0a-6) which matches the observed image. The published paper states: "Overall, the observed image is consistent with expectations for the shadow of a [spinning Kerr black hole](https://en.wikipedia.org/wiki/Spinning_Kerr_black_hole "Spinning Kerr black hole") as predicted by general relativity."[\[33\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-33) Paul T. P. Ho, EHT Board member, said: "Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter, and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well."[\[30\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eso1907-30) The image also provided new measurements for the mass and diameter of M87\. EHT measured the black hole's mass to be 6\.5±0\.7 billion [solar masses](https://en.wikipedia.org/wiki/Solar_masses "Solar masses") and measured the diameter of its event horizon to be approximately 40 billion kilometres (270 AU; 0.0013 pc; 0.0042 ly), roughly 2.5 times smaller than the shadow that it casts, seen at the center of the image.[\[30\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-eso1907-30)[\[32\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-sciencenews-32) Previous observations of M87 showed that the large-scale [jet](https://en.wikipedia.org/wiki/Astrophysical_jet "Astrophysical jet") is inclined at an angle of 17° relative to the observer's line of sight and oriented on the plane of the sky at a [position angle](https://en.wikipedia.org/wiki/Position_angle "Position angle") of −72°.[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[34\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-34) From the enhanced brightness of the southern part of the ring due to [relativistic beaming](https://en.wikipedia.org/wiki/Relativistic_beaming "Relativistic beaming") of approaching funnel wall jet emission, EHT concluded the black hole, which anchors the jet, spins clockwise, as seen from Earth.[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[14\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-aasnova-20190410-14) EHT simulations allow for both prograde and retrograde inner disk rotation with respect to the black hole, while excluding zero black hole spin using a conservative minimum jet power of 1042 erg/s via the [Blandford–Znajek process](https://en.wikipedia.org/wiki/Blandford%E2%80%93Znajek_process "Blandford–Znajek process").[\[2\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-APJL-20190410-2)[\[35\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-35) Producing an image from data from an array of radio telescopes requires much mathematical work. Four independent teams created images to assess the reliability of the results.[\[36\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-imaging-36) These methods included both an established algorithm in [radio astronomy](https://en.wikipedia.org/wiki/Radio_astronomy "Radio astronomy") for [image reconstruction](https://en.wikipedia.org/wiki/Image_reconstruction "Image reconstruction") known as [CLEAN](https://en.wikipedia.org/wiki/CLEAN_\(algorithm\) "CLEAN (algorithm)"), invented by [Jan Högbom](https://en.wikipedia.org/wiki/Jan_H%C3%B6gbom "Jan Högbom"),[\[37\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-H%C3%B6gbom1974-37) as well as self-calibrating [image processing](https://en.wikipedia.org/wiki/Image_processing "Image processing") methods[\[38\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-bnss,etc-38) for astronomy such as the [CHIRP algorithm](https://en.wikipedia.org/wiki/CHIRP_\(algorithm\) "CHIRP (algorithm)") created by [Katherine Bouman](https://en.wikipedia.org/wiki/Katherine_Bouman "Katherine Bouman") and others.[\[36\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-imaging-36)[\[39\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-39) The algorithms that were ultimately used were a [regularized](https://en.wikipedia.org/wiki/Regularization_\(mathematics\) "Regularization (mathematics)") [maximum likelihood](https://en.wikipedia.org/wiki/Maximum_likelihood "Maximum likelihood") (RML)[\[40\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-40) algorithm and the [CLEAN](https://en.wikipedia.org/wiki/CLEAN_\(algorithm\) "CLEAN (algorithm)") algorithm.[\[36\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-imaging-36) In March 2020, astronomers proposed an improved way of seeing more of the rings in the first black hole image.[\[41\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-NYT-20200328-41)[\[42\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-42) In March 2021, a new photo was revealed, showing how the M87 black hole looks in polarised light. This is the first time astronomers have been able to measure polarisation so close to the edge of a black hole. The lines on the photo mark the orientation of polarisation, which is related to the magnetic field around the shadow of the black hole.[\[43\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-43) In August 2022, a team led by [University of Waterloo](https://en.wikipedia.org/wiki/University_of_Waterloo "University of Waterloo") researcher Avery Broderick released a "remaster\[ed\]" version of original image generated from the data collected by the EHT. This image "resolve\[d\] a fundamental signature of gravity around a black hole", with it showing a displaying [photon ring](https://en.wikipedia.org/wiki/Photon_ring "Photon ring") around [M87\](https://en.wikipedia.org/wiki/M87* "M87").[\[44\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-44)[\[45\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-45) The claim has been subsequently disputed.[\[46\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-46) In 2023, EHT released new, sharper images of the M87 black hole, reconstructed from the same 2017 data but created using the PRIMO algorithm.[\[47\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-47) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/EHT3C279PressReleaseImage.png/250px-EHT3C279PressReleaseImage.png)](https://en.wikipedia.org/wiki/File:EHT3C279PressReleaseImage.png) EHT image of the archetypal blazar 3C 279 showing a relativistic jet down to the AGN core surrounding the supermassive black hole. In April 2020, the EHT released the first 20 microarcsecond resolution images of the archetypal [blazar](https://en.wikipedia.org/wiki/Blazar "Blazar") [3C 279](https://en.wikipedia.org/wiki/3C_279 "3C 279") it observed in April 2017.[\[48\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-EHT3C279-48) These images, generated from observations over 4 nights in April 2017, reveal bright components of a jet whose projection on the observer plane exhibit apparent [superluminal motions](https://en.wikipedia.org/wiki/Superluminal_motion "Superluminal motion") with speeds up to 20 c.[\[49\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-EHT3C279PressRelease-49) Such apparent superluminal motion from relativistic emitters such as an approaching jet is explained by emission originating closer to the observer (downstream along the jet) catching up with emission originating further from the observer (at the jet base) as the jet propagates close to the speed of light at small angles to the line of sight. [![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/61/EHTcentaurusA2021.jpg/250px-EHTcentaurusA2021.jpg)](https://en.wikipedia.org/wiki/File:EHTcentaurusA2021.jpg) Image of Centaurus A showing its black hole jet at different scales In July 2021, high resolution images of the jet produced by a supermassive black hole sitting at the center of [Centaurus A](https://en.wikipedia.org/wiki/Centaurus_A "Centaurus A") were released. With a mass around 5\.5×107 [M☉](https://en.wikipedia.org/wiki/Solar_mass "Solar mass"), the black hole is not large enough for its [photon sphere](https://en.wikipedia.org/wiki/Photon_sphere "Photon sphere") to be observed, as in EHT images of Messier M87\, but its jet extends even beyond its host galaxy while staying as a highly collimated beam which is a point of study. Edge-brightening of the jet was also observed which would exclude models of particle acceleration that are unable to reproduce this effect. The image was 16 times sharper than previous observations and utilized a 1.3 mm wavelength.[\[50\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-50)[\[51\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-51)[\[52\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-52) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/96/EHT_Saggitarius_A_black_hole.tif/lossy-page1-200px-EHT_Saggitarius_A_black_hole.tif.jpg)](https://en.wikipedia.org/wiki/File:EHT_Saggitarius_A_black_hole.tif) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Sagittarius_Astar_in_polarised_light.tif/lossy-page1-200px-Sagittarius_Astar_in_polarised_light.tif.jpg)](https://en.wikipedia.org/wiki/File:Sagittarius_Astar_in_polarised_light.tif) Sagittarius A\* in polarised light, image released in 2024 On May 12, 2022, the EHT Collaboration revealed an image of [Sagittarius A\](https://en.wikipedia.org/wiki/Sagittarius_A "Sagittarius A"), the supermassive black hole at the [center](https://en.wikipedia.org/wiki/Galactic_Center "Galactic Center") of the [Milky Way](https://en.wikipedia.org/wiki/Milky_Way "Milky Way") [galaxy](https://en.wikipedia.org/wiki/Galaxy "Galaxy"). The black hole is 27,000 light-years away from Earth; it is thousands of times smaller than M87\. [Sera Markoff](https://en.wikipedia.org/wiki/Sera_Markoff "Sera Markoff"), Co-Chair of the EHT Science Council, said: "We have two completely different types of galaxies and two very different black hole masses, but close to the edge of these black holes they look amazingly similar. This tells us that General Relativity governs these objects up close, and any differences we see further away must be due to differences in the material that surrounds the black holes."[\[53\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-53) On March 22, 2024, the EHT Collaboration released an image of Sagittarius A\* in polarized light.[\[54\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-54) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e7/EHTj1924-2914.png/250px-EHTj1924-2914.png)](https://en.wikipedia.org/wiki/File:EHTj1924-2914.png) A multifrequency view of the bent jet in Blazar J1924-2914.[\[55\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:1-55)[\[56\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:2-56) In August 2022, the EHT together with Global Millimeter VLBI Array and the [Very Long Baseline Array](https://en.wikipedia.org/wiki/Very_Long_Baseline_Array "Very Long Baseline Array") imaged the distant [blazar](https://en.wikipedia.org/wiki/Blazar "Blazar") J1924-2914. They operated at 230 GHz, 86 GHz and 2.3+8.7 GHz, respectively, the highest angular resolution images of polarized emission from a quasar ever obtained. Observations reveal a helically bent jet and the polarization of its emission suggest a toroidal magnetic field structure. The object is used as calibrator for Sagittarius A\* sharing strong optical variability and polarization with it.[\[55\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:1-55)[\[56\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-:2-56) [![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/NRAO_530_by_EHT_01.jpg/250px-NRAO_530_by_EHT_01.jpg)](https://en.wikipedia.org/wiki/File:NRAO_530_by_EHT_01.jpg) NRAO 530 by EHT. The total intensity is shown in grayscale with black contours indicating 10%, 25%, 50%, and 75% of the peak LP intensity. Black dotted contours indicate 25%, 50%, and 75% of the peak polarized intensity. [![](https://upload.wikimedia.org/wikipedia/commons/thumb/7/77/NRAO_530_by_EHT_02.jpg/250px-NRAO_530_by_EHT_02.jpg)](https://en.wikipedia.org/wiki/File:NRAO_530_by_EHT_02.jpg) Schematic of the total-intensity and LP components in the EHT fiducial image of NRAO 530; white contours show the total intensity levels; color scale and cyan contours represent the polarized intensity of the method-averaged image. In February 2023, the EHT reported on the observations of the [quasar](https://en.wikipedia.org/wiki/Quasar "Quasar") NRAO 530. NRAO 530 (1730−130, J1733−1304) is a [flat-spectrum radio quasar](https://en.wikipedia.org/wiki/Flat-spectrum_radio_quasar "Flat-spectrum radio quasar") (FSRQ) that belongs to the class of bright γ-ray [blazars](https://en.wikipedia.org/wiki/Blazar "Blazar") and shows significant variability across the entire electromagnetic spectrum. The source was monitored by the University of Michigan Radio Observatory at 4.8, 8.4, and 14.5 GHz for several decades until 2012. The quasar underwent a dramatic radio outburst in 1997, during which its flux density at 14.5 GHz exceeded 10 Jy, while the average value is ~2 Jy. Since 2002, NRAO 530 has been monitored by the Submillimeter Array (SMA; Maunakea, Hawaii) at 1.3 mm and 870 μm. NRAO 530 has a redshift of z = 0.902 (Junkkarinen 1984), for which 100 μas corresponds to a linear distance of 6 billion pc. The source contains a supermassive black hole, the mass of which is currently uncertain, with estimates ranging from 3×108 M☉ to 2×109 M☉.[\[57\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-nrao530-57) It was observed with the Event Horizon Telescope on April 5−7, 2017, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A\. The observations were performed with the full EHT 2017 array of eight telescopes located at six geographical sites. At z* = 0.902, this is the most distant object imaged by the EHT so far. The team reconstructed the first images of the source at 230 GHz, at an angular resolution of about 20 μas, both in total intensity and in linear polarization (LP). Source variability was not detected, that allowed to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which was associated with the core. The feature is linearly polarized, with a fractional polarization of about 5%–8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle about −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field.[\[57\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-nrao530-57) ## Collaborating institutes \[[edit](https://en.wikipedia.org/w/index.php?title=Event_Horizon_Telescope&action=edit&section=9 "Edit section: Collaborating institutes")\] The EHT Collaboration consists of 13 stakeholder institutes:[\[58\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-58) - the [Academia Sinica](https://en.wikipedia.org/wiki/Academia_Sinica "Academia Sinica") Institute of Astronomy and Astrophysics - the [University of Arizona](https://en.wikipedia.org/wiki/University_of_Arizona "University of Arizona") - the [University of Chicago](https://en.wikipedia.org/wiki/University_of_Chicago "University of Chicago") - the [East Asian Observatory](https://en.wikipedia.org/w/index.php?title=East_Asian_Observatory&action=edit&redlink=1 "East Asian Observatory (page does not exist)") - [Goethe University Frankfurt](https://en.wikipedia.org/wiki/Goethe_University_Frankfurt "Goethe University Frankfurt") - [Smithsonian Astrophysical Observatory](https://en.wikipedia.org/wiki/Smithsonian_Astrophysical_Observatory "Smithsonian Astrophysical Observatory") (part of the [Harvard–Smithsonian Center for Astrophysics](https://en.wikipedia.org/wiki/Harvard%E2%80%93Smithsonian_Center_for_Astrophysics "Harvard–Smithsonian Center for Astrophysics")) - [Institut de radioastronomie millimétrique](https://en.wikipedia.org/wiki/Institut_de_radioastronomie_millim%C3%A9trique "Institut de radioastronomie millimétrique") (IRAM, itself a collaboration between the French [CNRS](https://en.wikipedia.org/wiki/CNRS "CNRS"), the German [Max Planck Society](https://en.wikipedia.org/wiki/Max_Planck_Society "Max Planck Society"), and the Spanish [Instituto Geográfico Nacional](https://en.wikipedia.org/wiki/Instituto_Geogr%C3%A1fico_Nacional_\(Spain\) "Instituto Geográfico Nacional (Spain)")) - [Large Millimeter Telescope](https://en.wikipedia.org/wiki/Large_Millimeter_Telescope "Large Millimeter Telescope") Alfonso Serrano - [Max Planck Institute for Radio Astronomy](https://en.wikipedia.org/wiki/Max_Planck_Institute_for_Radio_Astronomy "Max Planck Institute for Radio Astronomy") - [MIT](https://en.wikipedia.org/wiki/MIT "MIT") [Haystack Observatory](https://en.wikipedia.org/wiki/Haystack_Observatory "Haystack Observatory") - [National Astronomical Observatory of Japan](https://en.wikipedia.org/wiki/National_Astronomical_Observatory_of_Japan "National Astronomical Observatory of Japan") - [Perimeter Institute for Theoretical Physics](https://en.wikipedia.org/wiki/Perimeter_Institute_for_Theoretical_Physics "Perimeter Institute for Theoretical Physics") - [Radboud University](https://en.wikipedia.org/wiki/Radboud_University "Radboud University") [![](https://upload.wikimedia.org/wikipedia/commons/thumb/1/10/Locations_of_the_telescopes_that_make_up_the_EHT_array_%28eso2208-eht-mwi%29.tiff/lossy-page1-1000px-Locations_of_the_telescopes_that_make_up_the_EHT_array_%28eso2208-eht-mwi%29.tiff.jpg)](https://en.wikipedia.org/wiki/File:Locations_of_the_telescopes_that_make_up_the_EHT_array_\(eso2208-eht-mwi\).tiff) Locations of the telescopes that make up the EHT array. A global map showing the radio observatories that form the Event Horizon Telescope (EHT) network used to image the Milky Way's central black hole, Sagittarius A\. The telescopes highlighted in yellow were part of the EHT network during the observations of Sagittarius A\ in 2017. These include the Atacama Large Millimeter/submillimeter Array (ALMA), the Atacama Pathfinder EXperiment (APEX), IRAM 30-meter telescope (30-M), James Clark Maxwell Telescope (JCMT), Large Millimeter Telescope (LMT), Submillimeter Array (SMA), Submillimetere Telescope (SMT) and South Pole Telescope (SPT). Highlighted in blue are the three telescopes added to the EHT Collaboration after 2018: the Greenland Telescope (GLT), the NOrthern Extended Millimeter Array (NOEMA) in France, and the University of Arizona ARO 12-meter Telescope at Kitt Peak. The EHT Collaboration receives funding from numerous sources including:[\[59\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-59) - [United States National Science Foundation](https://en.wikipedia.org/wiki/National_Science_Foundation "National Science Foundation") - [European Research Council](https://en.wikipedia.org/wiki/European_Research_Council "European Research Council") - [National Science and Technology Council of Taiwan](https://en.wikipedia.org/wiki/National_Science_and_Technology_Council_\(Taiwan\) "National Science and Technology Council (Taiwan)") (formerly Ministry of Science and Technology of Taiwan) - [Max Planck Society](https://en.wikipedia.org/wiki/Max_Planck_Society "Max Planck Society") - [Consejo Nacional de Ciencia y Technologia, Mexico](https://en.wikipedia.org/wiki/Consejo_Nacional_de_Ciencia_y_Tecnolog%C3%ADa_\(Mexico\) "Consejo Nacional de Ciencia y Tecnología (Mexico)") - [John Templeton Foundation](https://en.wikipedia.org/wiki/John_Templeton_Foundation "John Templeton Foundation") - [Gordon and Betty Moore Foundation](https://en.wikipedia.org/wiki/Gordon_and_Betty_Moore_Foundation "Gordon and Betty Moore Foundation") - [Japan Society for the Promotion of Science](https://en.wikipedia.org/wiki/Japan_Society_for_the_Promotion_of_Science "Japan Society for the Promotion of Science") - [Natural Sciences and Engineering Research Council of Canada](https://en.wikipedia.org/wiki/Natural_Sciences_and_Engineering_Research_Council "Natural Sciences and Engineering Research Council") - [Academia Sinica](https://en.wikipedia.org/wiki/Academia_Sinica "Academia Sinica") - [Smithsonian Institution](https://en.wikipedia.org/wiki/Smithsonian_Institution "Smithsonian Institution") Additionally, [Western Digital](https://en.wikipedia.org/wiki/Western_Digital "Western Digital") and [Xilinx](https://en.wikipedia.org/wiki/Xilinx "Xilinx") are industry donors.[\[60\]](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_note-60) 1. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-wp-2009_1-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-wp-2009_1-1) Doeleman, Sheperd (June 21, 2009). "Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole". Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers. 2010: 68. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0906\.3899](https://arxiv.org/abs/0906.3899). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2009astro2010S..68D](https://ui.adsabs.harvard.edu/abs/2009astro2010S..68D). 2. ^ [a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-1) [c](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-2) [d](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-3) [e](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-4) [f](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-APJL-20190410_2-5) The Event Horizon Telescope Collaboration (April 10, 2019). ["First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole"](https://doi.org/10.3847%2F2041-8213%2Fab0ec7). [The Astrophysical Journal Letters](https://en.wikipedia.org/wiki/The_Astrophysical_Journal_Letters "The Astrophysical Journal Letters"). 875* (1): L1. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1906\.11238](https://arxiv.org/abs/1906.11238). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2019ApJ...875L...1E](https://ui.adsabs.harvard.edu/abs/2019ApJ...875L...1E). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.3847/2041-8213/ab0ec7](https://doi.org/10.3847%2F2041-8213%2Fab0ec7). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [145906806](https://api.semanticscholar.org/CorpusID:145906806). 3. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-3) Bardeen, James (1973). "Black holes. Edited by C. DeWitt and B. S. DeWitt". Les Houches École d'Été de Physique Théorique. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1973blho.conf.....D](https://ui.adsabs.harvard.edu/abs/1973blho.conf.....D). 4. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-4) Luminet, Jean-Pierre (July 31, 1979). "Image of a spherical black hole with thin accretion disk". Astronomy and Astrophysics. 75: 228. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1979A\&A....75..228L](https://ui.adsabs.harvard.edu/abs/1979A&A....75..228L). 5. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-:0_5-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-:0_5-1) Falcke, Heino; Melia, Fulvio; Agol, Eric (January 1, 2000). "Viewing the Shadow of the Black Hole at the Galactic Center". The Astrophysical Journal Letters. 528* (1): L13–L16. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/9912263](https://arxiv.org/abs/astro-ph/9912263). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2000ApJ...528L..13F](https://ui.adsabs.harvard.edu/abs/2000ApJ...528L..13F). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/312423](https://doi.org/10.1086%2F312423). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [10587484](https://pubmed.ncbi.nlm.nih.gov/10587484). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [119433133](https://api.semanticscholar.org/CorpusID:119433133). 6. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-:0a_6-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-:0a_6-1) Broderick, Avery; Loeb, Abraham (April 11, 2006). ["Imaging optically-thin hotspots near the black hole horizon of Sgr A\ at radio and near-infrared wavelengths"](https://doi.org/10.1111%2Fj.1365-2966.2006.10152.x). Monthly Notices of the Royal Astronomical Society. 367 (3): 905–916\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[astro-ph/0509237](https://arxiv.org/abs/astro-ph/0509237). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2006MNRAS.367..905B](https://ui.adsabs.harvard.edu/abs/2006MNRAS.367..905B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1111/j.1365-2966.2006.10152.x](https://doi.org/10.1111%2Fj.1365-2966.2006.10152.x). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [16881360](https://api.semanticscholar.org/CorpusID:16881360). 7. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-7) Balick, Bruce; Brown, R.L. (December 1, 1974). ["Intense sub-arcsecond structure in the galactic center"](https://doi.org/10.1086%2F153242). The Astrophysical Journal. 194 (1): 265–279\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[1974ApJ...194..265B](https://ui.adsabs.harvard.edu/abs/1974ApJ...194..265B). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1086/153242](https://doi.org/10.1086%2F153242). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [121802758](https://api.semanticscholar.org/CorpusID:121802758). 8. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-Sheperd2008_8-0) Doeleman, Sheperd (September 4, 2008). "Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre". Nature. 455 (7209): 78–80\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[0809\.2442](https://arxiv.org/abs/0809.2442). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2008Natur.455...78D](https://ui.adsabs.harvard.edu/abs/2008Natur.455...78D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1038/nature07245](https://doi.org/10.1038%2Fnature07245). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [18769434](https://pubmed.ncbi.nlm.nih.gov/18769434). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [4424735](https://api.semanticscholar.org/CorpusID:4424735). 9. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-Sheperd2012_9-0) Doeleman, Sheperd (October 19, 2012). "Jet-launching structure resolved near the supermassive black hole in M87". Science. 338 (6105): 355–358\. [arXiv](https://en.wikipedia.org/wiki/ArXiv_\(identifier\) "ArXiv (identifier)"):[1210\.6132](https://arxiv.org/abs/1210.6132). [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2012Sci...338..355D](https://ui.adsabs.harvard.edu/abs/2012Sci...338..355D). [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.1126/science.1224768](https://doi.org/10.1126%2Fscience.1224768). [PMID](https://en.wikipedia.org/wiki/PMID_\(identifier\) "PMID (identifier)") [23019611](https://pubmed.ncbi.nlm.nih.gov/23019611). [S2CID](https://en.wikipedia.org/wiki/S2CID_\(identifier\) "S2CID (identifier)") [37585603](https://api.semanticscholar.org/CorpusID:37585603). 10. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-breakthrough-prize_10-0) ["Winners Of The 2020 Breakthrough Prize In Life Sciences, Fundamental Physics And Mathematics Announced"](https://breakthroughprize.org/News/54). Breakthrough Prize. Retrieved March 15, 2020. 11. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-website_11-0) ["Event Horizon Telescope 2022"](https://www.mpifr-bonn.mpg.de/announcements/2022/2). March 12, 2022. 12. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-eht-apjl-focus_12-0) Shep Doeleman, on behalf of the EHT Collaboration (April 2019). ["Focus on the First Event Horizon Telescope Results"](https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT). The Astrophysical Journal Letters. Retrieved April 10, 2019. 13. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-NYT-20210324_13-0) [Overbye, Dennis](https://en.wikipedia.org/wiki/Dennis_Overbye "Dennis Overbye") (March 24, 2021). ["The Most Intimate Portrait Yet of a Black Hole – Two years of analyzing the polarized light from a galaxy's giant black hole has given scientists a glimpse at how quasars might arise"](https://www.nytimes.com/2021/03/24/science/astronomy-messier-87-black-hole.html). [The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times"). Retrieved March 25, 2021. 14. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-aasnova-20190410_14-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-aasnova-20190410_14-1) Kohler, Susanna (April 10, 2019). ["First Images of a Black Hole from the Event Horizon Telescope"](https://aasnova.org/2019/04/10/first-images-of-a-black-hole-from-the-event-horizon-telescope/). AAS Nova. Retrieved April 10, 2019. 15. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-NYT-20220512_15-0)* [Overbye, Dennis](https://en.wikipedia.org/wiki/Dennis_Overbye "Dennis Overbye") (May 12, 2022). ["Has the Milky Way's Black Hole Come to Light? – The Event Horizon Telescope reaches again for a glimpse of the 'unseeable'"](https://www.nytimes.com/2022/05/12/science/black-hole-photo.html). [The New York Times](https://en.wikipedia.org/wiki/The_New_York_Times "The New York Times"). Retrieved May 12, 2022. 16. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-16) Alexander W. Raymond et al 2024 AJ 168 130 17. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-O'Neil2015_17-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-O'Neil2015_17-1) O'Neill, Ian (July 2, 2015). ["Event Horizon Telescope Will Probe Spacetime's Mysteries"](https://web.archive.org/web/20150905193743/http://news.discovery.com/space/astronomy/event-horizon-telescope-will-probe-spacetimes-mysteries-150702.htm). Discovery News. Archived from [the original](http://news.discovery.com/space/astronomy/event-horizon-telescope-will-probe-spacetimes-mysteries-150702.htm) on September 5, 2015. Retrieved August 21, 2015. 18. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-18)* ["MIT Haystack Observatory: Astronomy Wideband VLBI Millimeter Wavelength"](https://www.haystack.mit.edu/ast/uvlbi/mm/eht.html). www.haystack.mit.edu. 19. [^](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-19) Webb, Jonathan (January 8, 2016). ["Event horizon snapshot due in 2017"](https://www.bbc.com/news/science-environment-35258378). BBC News. Retrieved March 24, 2016. 20. ^ [*a](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-nature543_20-0) [b](https://en.wikipedia.org/wiki/Event_Horizon_Telescope#cite_ref-nature543_20-1) Davide Castelvecchi (March 23, 2017). ["How to hunt for a black hole with a telescope the size of Earth"](https://doi.org/10.1038%2F543478a). Nature. 543* (7646): 478–480\. [Bibcode](https://en.wikipedia.org/wiki/Bibcode_\(identifier\) "Bibcode (identifier)"):[2017Natur.543..478C](https://ui.adsabs.harvard.edu/abs/2017Natur.543..478C). 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Retrieved September 27, 2023. - [Official website](https://eventhorizontelescope.org/) [![Edit this at Wikidata](https://upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png)](https://www.wikidata.org/wiki/Q3944788#P856 "Edit this at Wikidata") - [EHT "Ask Me Anything" (AMA) serie](https://www.reddit.com/r/askscience/comments/olel36/askscience_ama_series_were_event_horizon_horizon/) on [reddit](https://en.wikipedia.org/wiki/Reddit "Reddit") - [The Next Generation Event Horizon Telescope](https://www.ngeht.org/)
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Root Hash	17790707453426894952
Unparsed URL	org,wikipedia!en,/wiki/Event_Horizon_Telescope s443